First Run: Garmin’s New Running Power Capabilities


Last week at the ANT+ Symposium, Garmin opened up the curtains on their planned entrance into the running power market, which they’ll soon make available on many running and multisport devices they make.  This app will require only a barometer-equipped watch that supports the latest Connect IQ version, as well a Running Dynamics capable HR strap or pod, both of which have been sold and bundled for years.

Now what’s interesting here is how exactly Garmin is planning on rolling this out.  This isn’t a new native feature to the watches.  Nor is it something that requires a new watch at all. In fact, it’ll work on some watches a number of years old.

Instead, Garmin is forcing themselves to develop the running power functionality via Connect IQ – in the same way that Stryd has been forced to utilize that same framework for their running power app and functionality.  This has both pros and cons though, as I’ll dive into below.  But it does effectively put both options on a level playing field from the standpoint of competitiveness.

If you want a quick overview of things, here’s a video I put together of my first run with it up in Banff, Canada and then a secondary run in Paris yesterday:

With that, let’s dive into all the details.  But note – this isn’t available yet.  It’ll be released around November 22nd, which is the date that the next version of Connect IQ (2.4) is released to the public.

What you need:

First, you’ll need to wait till November 22nd, due to the dependency on the next version of Garmin Connect IQ, which is the development platform update that was announced last week at the ANT+ Symposium.

That said, the requirements are pretty straightforward:

A) Connect IQ capable watch with a barometer that supports version Connect IQ 2.4: See the full chart down below.
B) Garmin HRM-TRI, HRM-RUN, or RD-POD: Any version, even ones three years old now.

Why these two and a half requirements?  Well, it’s a two-parter.  Let me explain:

A) Barometric altimeter requirement: This is required to know when you’re going uphill and downhill, which is in turn used in the calculations of power.  Stryd is much the same, except they just have a barometric altimeter inside their little pod (and older chest strap version).

B) Running Dynamics requirement: The requirement to have an HRM-TRI, HRM-RUN, or RD-POD is based on the need to get a number of metrics, but most notably Vertical Oscillation and Ground Contact Time, which are only available in those accessories.  The good news is those accessories have been around for about four years, and even the oldest straps will work. Note that Stryd also uses the same core Vertical Oscillation and related metrics.

C) Why Connect IQ 2.4? Ahh, this is an interesting one.  See, Connect IQ version 2.4 actually includes new native connectivity to the Running Dynamics (HR-RD) ANT+ profile from any Connect IQ app.  This means that any app can use this profile.  It also means that anyone else could actually develop a running power app if they wanted to, using the same Garmin devices.  The side effect to this requirement is that more inexpensive barometric altimeter devices (notably the Vivoactive HR) will get the CIQ update – despite not otherwise supporting Running Dynamics natively.  As such, they get running power. Note: The Garmin Fenix 5 and FR935 will receive Connect IQ 2.4 likely a few days later than other devices do. Just an FYI.

Want a list of Connect IQ 2 compatible devices? Here:


(I’ve crossed out the FR735XT, because it doesn’t have a barometer in it, so while it’s 2.4 capable, it’s missing the required barometric altimeter for running power.)

You’ll note devices like the Garmin Fenix 3/3HR aren’t on the list, nor the FR630 or FR920XT.  These devices stopped receiving the newer Connect IQ version almost a year ago.  That caused a ruckus at the time, since some of them were still effectively current devices (it was pre-Fenix 5 then).  A fair bit of that can, in turn, be attributed to those devices really being the first generation of devices Garmin launched Connect IQ, and thus some of the longer planning on what it takes to operate a software development ecosystem hadn’t fully materialized yet.  Here’s what the whole chart looks like.

Next thing is you’ll need the RunPow app.  Now, again, it’s not available yet.  And that name probably isn’t final (but should be).  But it reminds me of Caf-Pow, which Abby of NCIS is a regular consumer of.  Obviously, I’m an NCIS fan.


In any event, the RunPow app is technically a Garmin Connect IQ data field.  That data field, in turn, connects to the Running Dynamics accessory of your choice (HRM-TRI/HRM-RUN/RD-POD).  Here’s that app in all its simplicity on a Garmin FR935, as a data field atop another data field I’ve set for pace:


The app merely has one data field, which at present just shows your current power.  Yup, that’s it.

Below you can see me running along at 540w and a 7:20/mile pace on flat ground.


And this is where things get kinda interesting.  Like Stryd, there isn’t a way to implement things like 3-second power, 5-second power, or 10-second power (natively on the watch, only via configuration in the app for Stryd).  Nor is there a way to implement useful features like lap power.  It’s just one power field.

Certainly, Garmin could create multiple Connect IQ data fields, but many watches are limited to only two CIQ data fields being utilized at once.  Heck, they even limit you to not being able to re-use that same field on other pages.

And it’s at this juncture that Garmin is feeling some of the pain of their own doing.  Which isn’t to say Connect IQ is bad, it’s just that sometimes it takes eating your own dog food for an actual “product” to force you to realize the shortcomings and how it might make a product useful or not.  Or at least it makes you feel the pain.  These are all shortcomings that app developers and consumers have been complaining about for quite some time.

Garmin says there’s been about 15 running power related features related to their app they’ve had to forgo, due to the lack of underlying support for those things in Garmin Connect IQ.  Of course, they could have just natively built the whole thing into the product – but this is a good exercise for them.

At the Symposium, they outlined some features they can’t implement, largely due to Connect IQ:


To translate this from tech speak to English, here’s what these mean (they all apply to Stryd as well):

Two CIQ limit: Means you can’t put RunPow (running power) on multiple pages like you might put the same HR or pace on multiple pages.  One page only.
Doesn’t show up in history: You won’t see any running power stats at the end of a run, or in the history section of your workout.
Banners are limited: Simply put, no overlay banners for running power like you might see for things like lap averages.
Configuration within GCM: This means any configuration of the data field has to happen with Garmin Connect Mobile, you can’t tweak it on the watch itself.
CIQ fields can’t be used as intensity target: I think this is self-explanatory, but essentially you can’t set power targets with this like you could set pace or HR targets.
CIQ data doesn’t appear in reports: Since it’s not a normal field like pace or heart rate, you won’t get it in some of the fancy reports of Garmin Connect.

In any event – back to the run.  As you run, this power number will fluctuate just like Stryd’s does.  Run harder, and it’ll go up, go up-hills and it’ll go up assuming you’re putting out more power.


(Above: Differences between Garmin power (top), and Stryd power (bottom).)

There are some notable differences here.  In the case of Stryd, they appear to be doing a bit more smoothing in the data than Garmin, but not noticeably so when running (only when looking at the data after).  Of bigger concern is that both numbers are so different.  Garmin’s sits about 100-150w higher than Stryd’s does, for me, across a wide range of terrain and conditions.

All of which also calls into question the validity of any running power meter number today.  Simply put: There is no standard to compare to.  Yes, you can get force plate treadmills indoors – something Stryd has done and shown before in various circumstances.  But you can’t put those outdoors on a gravel hill into a headwind.  So nobody really knows what the power looks like there, or if the models are correct.  Not Garmin, not Stryd.

Further, even ‘direct force’ variants like Arion (more soon) aren’t measuring shear force, which is force that’s not directly down onto the unit itself.  So that’s yet another type of approximation. Potentially better, but it’s also hard to know for certain.

Post-run stats:

So let’s look at some data.  Now I should first point out that these stats are from screenshots taken on the Garmin beta servers (since the app is officially unpublished still).  Since I don’t have access to those, the Garmin folks took a crapton of screenshots for me to compare.  Inversely it also means the Stryd data doesn’t show up there.  So I’ve gotta blend two screenshots together to make this work.  Naturally, once published it’ll all be magical and on one page if you have two devices.

First though, ignoring comparative data – here’s what it’ll all look like on Garmin Connect within the charts section (it’s the very last line, you can click to zoom):


To put that in perspective, let’s overlay my running power with pace, atop elevation.  This first run is from the mountain I ran up.


You can see above that there’s a relationship between pace and power, as you’d expect.  However, there’s also a relationship to vertical oscillation and ground contact time as well.  These are all metrics that Stryd also leverages, and reports as well within the dashboard.

Here’s the exact same chart from Stryd (sorry, there isn’t a way to overlay them since they’re on different platforms right now).


You can see the two units roughly go up and down at the same time, but the intensity varies between them.

Note that you have the ability to see ‘Average Running Power’ for each of the laps/splits within my file (set at 1-mile intervals).  That’s shown on the right side:


And then down below in the run summary stats, you’ll see on the left side is a ‘Connect IQ’ section with the ‘RunPow’ app listed.  Here it shows the version, but also shows the Average Running Power for the run (270w).


I then did a run yesterday back in Paris on much flatter ground (and a bit more consistent in pace).  Here’s a look at that:

20171002 Ray RunPowChartAndSplits

My vertical oscillation was fairly high here, much higher than up on the mountain.  Also, my power was higher here, but I was also not doing as much stop and go as on the mountain, so that skews things a bit.  Here’s just the power chart from Garmin;

20171002 Ray Overlay1

And here’s the same thing on the Stryd front:


You generally speaking see much less variability with the Stryd side than Garmin (more smoothing if you will).  Now, deciding which one is most accurate?  Well…who knows.

If you want to look at all the screenshots sent over, here’s two galleries.  The first on the mountain:

You can look at my full Garmin Connect activity with the Stryd data here for the mountain.

And here’s the second set for 5K run in Paris:

As well as here for the Garmin Connect link with the Stryd data.

Ultimately there’s no easy way to know which one is most accurate. Both companies claim they’re backed by data and science.  While Stryd has shown some data from indoor treadmills and how it matches, neither company can demonstrate anything tangible outdoors because no such technology exists to base any sort of accuracy statement on outdoors.

Updated section – Oct 5th, 2017:

Just as an update to things, and mostly at the request of various readers in the comments below, Garmin has provided a slide of the various papers they’ve used as the basis for their work/algorithms.  Here’s that slide:


In addition, Garmin also shot over an updated/reworked slide of the limitations of CIQ slide I posted up above earlier from their presentation (still listed).  That slide up above actually was never presented at the Symposium.  It was in draft copies of the presentation, but not shown.  A few days following the summit I received a copy of the entire slide-deck to pluck out some of the Running Power slides, but it turns out I was sent the draft, and not the final.

The Garmin team didn’t ask for that slide to be pulled, but instead just wanted to provide a bit more context of the pros and cons of their thinking to me specifically.  I in turn asked if I could publish it here, and they were OK with that.  Remember, this slide is specifically talking to the pros and cons versus building out power in the watch natively versus doing it in a CIQ app.


Finally, Garmin notes that there will be some configuration options via the Connect Mobile app, including aspects related to power zone fields.  I didn’t have the opportunity to test/try those, but will report back on them once things are released in November

Thoughts on running power:


When Garmin announced running power at the ANT+ Symposium last week, they seemed to take pains in the presentation to talk about how they got there and where they see themselves in the market.  In many ways, it appears that the introduction of running power is for them as much of a forced experiment in how to improve Connect IQ as a platform, as it is about introducing new functionality to their wearables lineup.

To be super clear here, with CIQ 2.4 coming out, any company can write the exact same app as Garmin (perhaps even better than Garmin).  They can leverage the exact same Running Dynamics data – heck, even from non-Garmin sources.  Some might see this as propriety Garmin stuff, but ultimately that’s actually the exact inverse of what’s going on here.  In fact, I’d argue Garmin should have done it internally in a firmware update, because it’d have probably been a heck of a lot better functionality wise (in the short term).  But in the long term this will force Garmin to make the CIQ platform better for others.  And that’s better for everyone, most notably consumers.

Which ultimately brings us back to Stryd (and others).  Like it or not, Garmin just made itself a competitor to Stryd.  For pure running power and RD metrics, that means Stryd costs roughly three times as much as Garmin for the exact same data (RD-POD is $69, versus Stryd at $199).  Stryd would (rightfully) argue they have a wider online platform in running analytics.  And that’s definitely true.  Whether or not it matters to the majority of the population that may just want a simple running power number is a much harder question to answer.

I’m also not going to make a judgment about which is more accurate. Anyone who does is kidding themselves.  There’s simply no way with today’s technology to know outside which is more accurate.  You can judge consistency, you can judge how variables and conditions impact each unit, but you can’t reliably judge accuracy today outside.

The other small tidbit to come out of this is that it sounds like an ANT+ Running Power TWG (Technical Working Group) is finally being formed.  That’s the first step to getting an official Running Power profile in process so that the data can be better supported.  Of course, this is really up to the member companies to push though.  That means the onus is on Stryd, RunScribe, and even Garmin to get that solidified.  Any of these companies by themselves can push and make that happen very quickly…if they want it.

But the biggest takeaway today?  Garmin’s thrown its weight behind running power.  There’s still plenty of work technologically and from a training perspective to be sorted out in the running power world (heck, there is already a full book on it!).  But with Garmin set to make it a baseline in almost all of their running products, it’ll certainly draw attention to it.  That attention may in turn help to sift through some of the technology and scientific aspects needed.

With that – thanks for reading!


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  1. Ryan M.

    Interesting. Also nice that once the updates are available it’s almost like a freebie for people who have the RD-Pod/HRM-RUN and compatible watches.

  2. Eric

    I assume the leg up that Stryd has is that it can also report pace as well? Is it still true the run pod can’t do pace? (love the Stryd on the treadmill, lets me track runs through my normal mechanisms — collecting directly on the phone with iSmoothRun).

  3. Nighthawk700

    I’m not a strong enough runner that I think Running Power would ever be useful for me, but I liked what you highlighted about this being a good lesson for Garmin in making CIQ better for all developers (including themselves). It can only result in better apps for Garmins, which in turn gives Garmin more power in the fitness watch marketplace. Slightly off subject, but did you say that at some point you were going to write a post about footpods? (either the stand alone, or the RD-Pod?) Next year I’m targeting a race that goes through a tunnel for 1 mile, so I’m looking into getting a footpod, Since your post mentioned the RD-Pod, it reminded me.

  4. Josh

    Technically shouldn’t the following read “unlike” versus “like”: Like Stryd, there isn’t a way to implement things like 3-second power, 5-second power, or 10-second power.

    • Eli

      Both of them can’t do those types of rolling averages

    • Eli

      I stand corrected:
      link to apps.garmin.com
      February 2017:

      You have the ability to show:
      1. Real time power
      2. 3 second power
      3. 10 second power
      4. 30 second power
      5. Lap power
      6. Total average power

      How can I access this new feature?
      1. Open Garmin Express
      2. Click Manage Apps
      3. Select Stryd Power
      4. Select an option to average your power

    • True, but I’m specifically referring to the ability for a user to self-select the smoothing/average option for the data field like any other data field on the watch.

    • Paul D

      I see that as a function of the watch – not the power mater. The Stryd Summit foot pod does a 5-second moving average (the Pioneer used to do 10s) to get a just-useable but very reactive reading. And then on my watch Suunto Spartan I can choose to average that for another 3, 10 or 30 seconds.

  5. Current devices will get the functionality via CIQ, but what about future devices? Will they get the running power baked in natively? Also, will the RD-pod work with the Stryd Data Field and the Stryd pod work with the Garmin Data Field? Or will that only be the case if Stryd updates their side to use the new RD ANT+ standard?

    • Miro

      To extend Justins question. Since power from Stryd or from RD-Pod is just an IQ field, can you record both at the same time?

    • At this point there’s no ANT+ standard for running power (search below for my thoughts, use the word ‘TWG’).

      Any future devices would of course get CIQ 2.40 though.

  6. Miro

    Interesting development.

    I do believe one other key limitation is the inability of one data field to reuse the data from another data field. The use case would be that I use one of the many multi-field data fields being able to display power from either the Stryd or Garmin power field. Right now I’m forced to switch between the multi-field data display over to another screen for power.

    But as you mention, nothing would prevent the multi-field developer from implementing thier own power, but I just don’t see that happening.


  7. Daniel O

    Very disappointing garmin has abandoned the 920XT. it is only 1 generation old and their flagship triathlon watch till recently.

    • Miro

      True, but i suspect the 920 simply lacked the CPU and memory to keep up with the newer version of IQ.

      But on the positive, its a great excuse to uprade to a new toy, I mean tool.

    • Dom

      Memory has a lot to do with it, see the table here. The overhead for data fields was getting pretty bad in the later versions of CIQ 1.x. Various benchmark apps on the Garmin app store show at least double the speed on newer watches.

  8. gingerneil

    I really hope that ant+ or garmin themselves get properly hold of this. Their approach here feels like the results of a panic brainstorm session where a few engineers have lashed up a capability out of whatever was available.
    I never use instant pace, preferring lap pace. Glancing down and seeing a number, relevant only for that instant, has always felt a bit pointless to me. I pace my efforts over a mile or a track lap.
    However, saying that, I *do* use instant heart rate as a guide to effort, mainly to slow me down on long runs.
    Maybe I’ll use power in a combination of these two approaches. But to enable me to do that, it needs to be built properly into my 935 and not added as a reactionary bodge. I need instant/lap/overall etc numbers.
    Runscribe Plus ships this week and they are also using connect iq. This could get messy! Worth only two fields available, I envisage lots of single fields that actually contain multi fields being used.

  9. Claus Jacobsen

    the article’s not showing on the “blog” page as an entry – got here through YT.

    But a bit sad – just bought the 735XT. (was a VERY good price at 252USD in Denmark though)

  10. Sean

    annnnd which watch do I have? 735XT.

    Story of my life, lol. How about a giveaway Ray, I think we’re due? :)

    • Steven Shaw

      Wow, I was almost about to buy a stryd, but I now think this looks more interesting, even though my Fenix 3 will need upgrading. Just the excuse I need to get a 935.

      Silly question but could I use my edge 520 this in the interim? Perhaps attached to my wrist using an old 910xt quick release. Not sure if it would work with the running dynamics stuff.

    • Paul Oliver

      Same question I had… Lol

    • It’d require Garmin release the app to the Edge devices, which realistically they probably wouldn’t do – merely for QA/testing overhead reasons.

    • Ben

      Wearing an Edge 520 on your wrist would be the funniest watch ever :-)

    • Scott

      It’s probably still smaller then the initial forerunner!

  11. Brian

    I’m a Stryd user and I’ve sort of seen this coming for awhile now. Garmin has been notoriously difficult in cooperating with the Stryd pod, but this is at least a good sign that will soon improve.

    Tough sell for Stryd with their $199 footpod when you can get the same functionality from the $69 Garmin footpod. Of course, you’d need a Garmin watch with a barometric altimeter, which as you noted many of them don’t.

  12. Brian

    Ray – Slight correction on your post, you CAN have 3sec, 10sec, lap, etc power from Stryd, they added that a few months ago.

    The caveat being, regardless of how many CIQ fields you’re already showing, you can only pick one metric from Stryd (I use 3sec wattage).

    • Yeah, I was talking natively within the watch itself. But I’ve clarified in the post.

    • Robert

      And that’s something Garmin should do prior to release – at least let the user select *which* version of the CIQ field he wants, if he can only display one. I would imagine that a 3 or 10 sec would be more useful than an instantaneous number in most cases, and lap for short interval work.

  13. The “Swirling F U” to users of even one-generation old products like the Fenix 3HR. I don’t blame them, but I’m not happy about it. This kind of behaviour will only encourage buyers to essentially only buy brand new products in order to get the most life out of them before new functionality in new devices makes still-excellent devices out dated. Especially seeing the Edge 520 – a product that is older than the Fenix 3HR – on the list really grinds my gears.

    • Robert

      That’s the flip side of opening up a part of the software platform to 3rd-party apps. You can’t predict initially that you will have an app store that will have some success, and how much business it will drive; once you release it, you have people who want more and more (and the article above talks at lenght about CIQ 2 limitations – let alone CIQ1), but the hardware can’t support it… Try running today’s IOS apps on the original iPhone… So you have to establish ‘cut points’ where you drop the backwards compatibility. IOS 11 runs on iPhone 5s, but not on iPhone 5, for example.

    • Craig

      I hate Garmin. When are they going to start respecting the customers that keep them in business? It’s always a losing proposition; buy new released products and endure endless software glitches, or buy a mature product and find it is no longer supported. Utterly useless!

  14. Brian

    Ray – Just noticed in your Garmin Connect graphs…How are you getting that “Ground Contact Balance %” metric? Is that something the Running Dynamics chest strap captures?

    If so, how does it know left from right?

  15. Mike Trudell

    Thanks Ray! Awesome write up as usual. Do I understand this correctly that there still isn’t a way to complete interval targets similar to cycling with any of the Garmin family of watches? Do you envision any IQ apps being released where you could build a workout which displays target “running watts”?

  16. Andrew

    While we can’t say that Stryd is absolutely accurate it’s pretty good. If Garmin is 100w+ higher that Stryd then I’m going to guess Garmin is wrong. Especially given that Stryd has demonstrated that their treadmill power ratings at least are accurate. We can calculate estimated power after a run by simply knowing the athlete’s weight, distance, and time (I’d assume this is similar to what Strava does for cyclists). I know you don’t have the files yet to work with but I’ll bet once you do we’ll see that Garmin’s number just doesn’t fit the physiology.

    All that being said, has Garmin commented on your accuracy? Being that far apart I would wonder if your pod was miscalibrated or weight was incorrect.

    • Garmin has seen it, and doesn’t believe it’s incorrect. They’ve also seen the Stryd data concurrently. In a nutshell, both companies believe their algorithms are correct per various studies.

      Garmin did note that the Vertical Oscillation figures on my Paris run seemed slightly abnormally high, which would in turn impact the power numbers if incorrect. I may for fun try using an HRM-TRI/RUN strap and see if that differs from RD-POD, just for the heck of it.

    • I had fairly different results between my mk1 and mk2 Stryds: I was told the footpod is more accurate because there’s more instability introduced with a chest strap (paraphrasing wildly here) so I’m guessing you should compare the HRM-Run vs the Garmin footpod vs the Stryd and see if that makes it even more confusing…

    • Yeah, I saw differences as well between Gen1 and Gen2. Someday when I’m sufficiently bored I’ll probably do a test run with all of them. At the moment though I’m working to get through the Vivoactive 3 and Apple Watch reviews.

    • Andrew

      I have a gen2 Stryd and I know anecdotally that people were seeing in the neighborhood of a 5% difference from gen1. This looks to be closer to a 50% difference. That go from “This isn’t an exact science” to “Are we even measuring the same thing?” Curious if this difference is consistent across more runs/devices and if there’s anything to the large VO.

    • D Walker

      My gut feeling is that I believe more in the correctness of the Stryd power number than the Garmin one. This is just based on personal experience with bike power meters and rowing ergometers. Running at Ray’s pace (even briefly. which is about all I can do) doesn’t feel anywhere near 450W of perceived exertion. 450W on the bike feels much more difficult to me and even 250W on the rowing machine feels much more difficult. So, I guess I’d like to see some lab data or other data from Garmin justifying the value. Under similar conditions Stryd and Garmin ought to be at least close. Which they aren’t right now.

    • Paul S.

      I agree with your gut feeling, but mostly because it’s new, and it’s Garmin, so there’s bound to be bugs, and Stryd has been doing this a while.

      But should cycling power have the same perceived effort as running power? That I’m not so sure of. I’m not a runner, but since this posted I’ve been thinking about this again (I am a Ph.D in Physics, although nothing remotely related to exercise physiology). For example, a cyclist and a runner approach a stop sign where they’re going to have to stop. The cyclist stops pedaling, so his power output immediately drops to zero. But since bicycles are low friction devices he continues moving until he applies the brakes. The brakes do work and generate power, but no one would worry about measuring or crediting the cyclist with this power since in a sense he’s already been credited with it, so the power measured during the stop is zero. The runner, on the other hand, has to continue running. There’s still vertical oscillation (maybe even exaggerated), a force opposite to the direction of motion has to be applied by legs/feet, so the power meter should continue to measure a power output. (Correctly? I’ve no idea.)

      Or consider downhill. The only reason to ride (slowly) a bicycle to the top of a mountain is to go back down it again. I’ve been passed on my mountain bike by runners going up steep climbs, but I can be sure that if I’m with or near them at the crest I’ll never seen them again on the descent. My power output will be zero or close to it for as long as the downhill lasts. But a runner can’t stop running and has to stay in control, so they’ll have to continuously bleed off the gravitational potential energy with their legs/feet (depending on the surface, I might have to on my MTB as well, but I’ll use my brakes). So there’ll still be measured power output in that case for a runner and not a cyclist.

    • Robin

      Slightly relevant to this comment – A sports scientist told me that HR zones for running are 10-15BPM higher than for cycling. Therefore it would make sense that for a given power number, the perceived exertion would feel higher running than cycling.

    • John

      @Paul S.:

      The only reason to ride (slowly) a bicycle to the top of a mountain is to conquer the mountain.


    • Ben_i

      Ray, thanks for the review!
      May I suggest a experiment to identify which may be more accurate?

      My hypothesis is that heart rate under constant conditions is a decent surrogate for energy expenditure (integral of power). Therefore if you have a well known running track, you could do a constant heart rate run (something I’m pretty sure you have locked down), ideally over some varying inclines and see if power also remains constant on both units. If one of the units shows wild variations in power, even though you know you maintained a balanced effort, it would indicate some issues in the algorithm.

      Alternatively, you could run up/down some constant inclines at a constant pace and see how well power correlates to the leveled-out heart rate (this might be harder to find the right testing ground).

      Well, this is what I would do if I had both units at my disposal.

    • Mike Richie

      You … are … the man!
      Looking forward to your reviews as I compare my new Apple Watch to my tried and true Vivoactive HR. (TL;DR, the Vivoactive is much better at fitness, but the Apple Watch is, well, …Just Fun ;)

    • Mike Richie

      Ha ha, was replying to Ray’s comment above, before all the intervening comments interceded.

    • Paul D

      Did you run the ~10min calibration on your old Stryd Pioneer? After I did that I found the Pioneer and Summit to be within 10w of each other. Of course then Stryd added better downhill power estimates to the Summit and the two separated.

    • Zoltan

      To Paul Re: “The brakes do work and generate power, but no one would worry about measuring or crediting the cyclist with this power ”

      As regards measuring you are wrong, see Isaac software from Velocomp (Newton/Ibike) at link to ibikesports.com

      Search for ‘braking’

    • Paul S.

      Yes, I know. I use a PowerPod and Isaac. You can see it in Isaac. But if they’re actually crediting it to me, they’re simply wrong, and I’ll have to stop using the PowerPod (or my new AeroPod).

  17. Christina B

    Any tips for making the running pod more accurate? I’d much rather run with just the pod for non-races (since I have the optical HRM on my 935, but I’ve found that the GCT and Vertical oscillation reading are alllll over the place (compared to when I wear my HRM strap). I’ve tried wearing bottoms with a tighter waistband, which helps a little, but it is still significantly off what my HRM strap shows. Is it just not designed for someone with a little “junk I’m the trunk”?

  18. Rafael Neves

    Is it correct to assume that the calculated power data will also be available in Garmin Connect to those devices that implement running dynamics but don’t support IQ Connect 2 (like the Fenix 3 and FR920XT)? If I understood correctly, they do gather the necessary data, just aren’t able to process it in real time, right?

    • No plans there that I’m aware of.

    • Adam

      You would think this would be theoretically possible and it’d be amazing if Garmin did this, but I can’t see it happening for two reasons:

      (1) It would double their workload, having to implement power calculation in both an ad-hoc (in the CIQ app) and post-hoc manner (on the server-side after upload to GC) and introduce possible conflicts for those devices that *are* calculating/recording it in real-time.

      (2) It would remove the incentive people might now have to upgrade from older devices such as the fenix 3.

    • Not doing it creates an incentive to buy not-Garmin next time around.

  19. Occamsrazor

    Very interesting read, thanks. The 2 x CIQ data field limitation is really annoying, even on Fenix 5. There’s some nice ones that record into the FIT file but you have to choose only two. Can the hardware really not handle more? Is there any chance they will up the limit? Thanks.

  20. Crispin E.

    Ray, have you got an early copy RunSribe Plus to start adding in to the comparison mix? (I ask as I’m tracking my RS Plus shipment dispatched yesterday…. can’t wait). It seems us consumers are going to suddenly be swamped with differing power sources and not sure which will be most useful. I agree accuracy is just guesswork, but winner must be the unit that best allows you to trace a constant power output to maintain a best effort over a given race distance or training target.

    • I don’t have a unit yet. Though, I did order one. Hmm, will have to check on tracking – odd.

    • Crispin E.

      I did put my pre-order in very shortly after it went live on the RS website, so maybe that’s why I’ve been lucky to be early in the dispatch queue. Tracking shows as having landed in UK, so fingers crossed it arrives in the next couple of days before heading off on a work trip.

  21. Lawrence Mize

    Assuming its flat ground and no headwind there is an equation to calculate horizontal power. Obviously this wouldn’t help you assess their ability to measure power outside, but would work on an indoor track. Like testing a cycling power meter on a trainer..it’s the easiest there. Think we could give it a try and see which one is more accurate. One must be with the differences being like that.

  22. Wojtek

    Just a thought – Stryd is not compatible with Garmin flagship watch – and Garmin is now competition to Stryd…

    • I do get the feeling Garmin feels moderately bad about that. It’s pushing people away from buying a more expensive watch at the expense of a cheap accessory. It sounds like by time all the right people realized how big an issue it was, it was too late to change. And it sounds like changing what’s in-watch right now from a manufacturing standpoint is more difficult than they would have hoped.

    • Scott

      Stryd is not compatible with the 935?

    • It’s fully compatible.

  23. Lars Ejaas

    I gave up on using Garmin and STRYD – just to many limitations!
    Sounds like Garmin is coming out with their own “halfway” solution.
    I for sure haven’t regret switching to Polar V800 instead. Native powersupport for running is just way better than Connect IQ.

  24. Steven Shaw

    Having re read this article, why didn’t Garmin do this properly? I mean without being to set power targets for workouts etc it has the same limitations as the stryd app. At least stryd has Powerace which allows you to follow a set power.

    I would have thought Garmin would have incorporated power natively such as measuring heart rate rather than using connect iq. This feels more like a hobbyists project than something developed by the watch’s manufacturer. Did they just put their name on someone else’s work? I’m guessing not since it uses a yet in released version of connect iq unless or do developers get beta versions of it.

    • One could argue they didn’t do it natively to force a 3rd party to bring the standard to market via ANT+ TWG. That’s better for consumers actually, in the long term. But more painful in the short term (as outlined in the post).

      As for putting their name on others work, everyone is using various published papers on this. The calculations aren’t that difficult.

      Developers should shortly get access to that CIQ version (I thought it was supposed to go live a few days ago, but maybe got held for some reason temporarily).

    • Paul S.

      Ray, do you have links to those papers? I’m curious. (Of course, they’ll probably be behind journal paywalls, but I thought I’d ask.)

    • I’ll see if I can get what Garmin is specifically using, as they noted it a few times in their ANT+ presentation. I believe Stryd lists theirs somewhere on their site…

  25. It would be interesting to compare a critical power test (one of the various versions) between Garmin and Stryd. While I agree you can’t really know which one is right, I suspect as long as you stay within a particular system then you’re probably going to be ok. I wonder if the discrepancy could be because Stryd is only measuring one leg?

    The thing I’m most disappointed in is the inability to use as an intensity target. I’ve been a Stryd user since the Kickstarter and not having that is my biggest limitation to using power for training. Do you have any sense that Garmin might be addressing that particular shortcoming any time soon? Thanks.

  26. Paul Oliver

    Since consistency is what matters in this case (not which one is accurate between Garmin & Stryd), I heard Garmin will be using GPS for Speed as opposed to Sryd, and GPS might be affected by several factors (signal, weather, buildings, etc), I wonder how much consistency will Garmin have vs Stryd. Whether an existing Garmin user with a compatible technology cares or not, only time will tell. I suspect for sure serious data users, this would be a key factor to choose between both platform.

    • ChrisR

      I read that Stryd is very accurate to calculate speed on treadmill. Is this related to what you just wrote? Would it be an incentive to go with Stryd (if you are doing some treadmill run)?

  27. Aaron

    An obvious move; it was just a matter of time, and Stryd should have (hopefully) expected it.

    It will be interesting to see how this shakes out and how the half million in venture funding that backed Stryd will react. It seems like there is a window that will quickly close…

  28. Milt MacFarlane

    G’day Ray great read, WKO4 are working on running power data, to give meaningful charts on it recently, will a watch (mine at the moment a Fenix 2 with a HRM-Run strap) it gives the running dynamics on ConnectIQ already, will it transfer the new data to TrainingPeaks then onto WKO4? Thanks

    • WKO4 is doing some good work here.

      I haven’t played with it recently, but my understanding is that it can enumerate any developer fields recorded, so this is just another one in that sense. I’ve gotta load it on my laptop again (switched laptops) to see how it handles here.

  29. Thomas

    If only Garmin would open up for power in running profiles, a lot would be sweet…

  30. Thomas Shaw

    Suspect that is pretty much the end of Stryd then!

  31. J. Gramm

    So, that pretty much confirms that Fenix 3 is dead for them?

  32. Fabio Adurno

    A revolution just began.

  33. Tim Grose

    Interesting. Thing I found with the Stryd power numbers that they were at least similar to my bike power numbers so made some “sense”. So my bike FTP is around 300W and if I ran at 300W (according to the Stryd) then I was putting in a fair bit of effort and I got to about 330W average in a flat out 10K race. It looks with the current Garmin algorithm I might be past 400W and maybe up to 500W. Do 500W on a bike and I am basically doing a short sprint. If both think they are measuring the same thing can’t both be right but maybe they aren’t the same thing? For instance, I recall Stryd talks about breaking down running power into not only an overall power that is the main one you see but into a component that is actually used to drive you forward and a component that is “wasted” in lateral and vertical directions (form power I think).

    • Steven Shaw

      I wondered about that, it’s fair to say that on average you use more energy per hour running than cycling, so since energy = power X time, it would follow that the average power numbers would be higher.

      How much of that energy is useful who knows since running is far less efficient than running. I suspect you are right in that the stryd is measuring more useful power (as in cycling where it is the energy transferred per second to the cranks) rather than the total power expended.

    • Lawrence Mize

      Power already figures time… Power = work/time. But you don’t need to calculate power to figure calories burned in running, rather how much oxygen is being used. We only use power to equal calories in cycling because the ratio is the same and power is easier to determine than oxygen expenditure is for cycling.

    • Comparing bike power and run power is apples vs grapes.

      Primer on running power : link to georgeron.com


  34. Matthew


    Two things:
    1). This post doesn’t show up for me on your site. I only found this because it showed up in my RSS feed
    2). Will you be posting a video & slides from your Ant+ keynote this year, like you’ve done in the past?

    • 1) Seems to be a recurring issue in last week or so. Devs been working on it. Sorry!

      2) Yup! As soon as I get a copy of the video from the ANT+ crew.

    • Matthew

      If it helps on #1: This post kept appearing / disappearing for me last night, and the comments as well. On the comments: I would look at this post – zero comments; hit refresh – 42 comments; hit refresh 1 comment.

      Really looking forward to your Ant+ keynote.

    • Yeah, it’s all a caching engine thing. Much of the site is cached, which is usually purged on a per-page basis as soon as a comment posts. But there’s been issues lately where the caching engine thread hangs, and basically nothing refreshes – thus resulting in what you and others are seeing.

      In general, logged in users bypass the cache (not due to preferential treatment or anything, just the way the thingy works), so I don’t tend to catch it as quickly. It’s also why some see it and others don’t.

  35. Steve Martin

    Interesting indeed.

  36. Sean McLean

    Annnnd, what watch do I have? The only one not supported! Time for another giveaway, Ray!

  37. tfk

    I thought this was a bit disappointing. (Garmin not you ;-) )

    I had hoped that whenever this was announced by Garmin all the current CIQ limitations would be blown away by a proper running power profile (that allows alerts, etc). that’s one thing that makes adoption of running power harder at present.

    PS STRYD can be configured to average the power displayed through Garmin Express, from memory in the data field config view

  38. Thomas Hunt

    Yay. Looking forward to this. Fenix 5 and FR935 getting firmware later? Is this something garmin told you? I guess they use the same base firmware. Suprised the arn’t first as the flagship.

    • It was noted specifically on the slides that way.

    • David

      Garmin sure knows how to treat their buyers of their most premium expensive products.

      My Fenix 5S Sapphire looks awesome and cost me a fortune but it’s been buggy, GPS performance is worse than my old 235, it doesn’t work *at all* with my Stages PM or Stryd footpod and new features that come to products like the Vivoactive 3 or Vivosmart come to our watches months later.

      It’s been frustrating, somehow I though Fenix users would get something better. I’m very excited by running power but I feel like this is only a partial solution before it gets backed into the firmware of some future watch we will have to upgraded to, maybe even if just to get the same ANT+ performance that products 1/4th the cost from Garmin have had for years.


  39. Susan

    This isn’t showing up on the home page for me. I only found it through your post on Facebook.

  40. Nice to see ! I hope that more running power meters are to come. But more over, I wish we’d see apps/software to exploit and analyze all this data.
    Do you ever plan to review the Stryd Power meter ?

  41. Eli

    So power here is saved as a custom developer field in the FIT file and not to the power field as set in the FIT standard? Makes it easy to have stryd and this at the same time to test. Also means apps that want to use this power data have to have code that recognizes Garmin’s custom data field

    • Correct, same as Stryd in using developer fields. Stryd also transmits power to faking the cycling profile. But that requires you be in cycling mode on a Garmin, which sucks for other reasons (none of which are Stryds fault).

  42. Guillermo

    Thanks for the note DCR, I’ll be looking forward to test the running dynamics.

    About the ANT+ symposium. Did they cover other topics like standards for Cycling Dynamics data over Bluetooth?

    • I’ve got another post coming up on more details, just kinda alternating Interbike leftovers with new stuff. You won’t see Cycling Dynamics over BLE coming from the ANT+ folks (that’d be from the BLE folks). But you will definitely see some news on Cycling Dynamics. Definitely good news.

  43. Dr. D

    Ray – I am not seeing this post on your site directly on my laptop. I picked it when via YouTube.
    I have Google Chrome/MS Edge.

    I am however seeing it on my phone via its Chrome browser.

  44. Robert C

    I can’t believe that I would not be able to use my fenix3HR for this. Such is life I guess

  45. Martin Perry

    Will there be a video of your ANT+ keynote online somewhere this time?

  46. Martin Steen Mortensen


    Nice to see Garmin begin to play around with this!
    Do you think that native integration of power on the garmin watches is something that will be implemented in the (near) future, and if it comes would you expect it to be added to current watches or only future updates?
    A fully integrated running power would be something that could make it worth it to postpone a watch upgrade.

    PS: last word in the penultimate line is straw, should this have been draw??

  47. Jan Magnus Brevik

    I’m stil on the 630, but preorded the new RunScribe plus. So wil be in the running power business soon. Is there a RunScribe plus review coming in the pipeline?

  48. JR

    To your knowledge, do the RD Pod and HRM-RUN strap have the same kinds of accelerometers as Stryd? I was under the impression that the key for Stryd was just much more accurate hardware (which is why a lot of people apparently use Stryd just to get instant pace).

    Also, I recall that you said the Fenix 5 had trouble with Stryd. Has it worked well with the RD Pod? Because while disappointed Stryd owners are probably a fairly small group for Garmin to deal with, I could imagine it being a much bigger problem for them if they roll out a feature like this in-house and it doesn’t work with their flagship product.

    • I haven’t really heard of any RD-Pod issues with the Fenix 5 (widespread anyway to my knowledge). Part of it is really just a distance thing there. The RD-Pod is half the distance from the watch as Stryd.

    • Wojtek

      You probably refer to well known ANT+ problems – actually no problems with my Adidas micoach Ant+ footpod and Fenix 5

    • David

      well stryd (and my stages pm) never worked *at all* (less than 10% of data properly recorded) with my Fenix 5S sapphire. i’ve used the garmin hrm-tri and garmin footpod with no issue.

      i *just* purchased the garmin rd-pod the moment i saw this post a few days ago (because i often run without the hrm-tri and until now didn’t see the value in the rd stats but i do want power on all my runs) and have now done 2 runs with my fenix 5S… both runs look great from connection standpoint.

  49. Thomas

    Hi Ray,

    This post is not showing up on your webpage for some reason. I can get to it from FB and from my RSS feed but not from your webpage.


  50. David Chao

    Super interesting that they went with CIQ fields. Coming from software engineering myself, I’d wonder if part of this is due to issues of managing code changes across a large codebase (and large engineering team) – i.e., forcing their internal team to consume their own API (dog-fooding it) is a tactic to just get the feature out the door as opposed to marketing-inspired.

    Another note – something I really value about the Stryd footpod is how crazy dead on (and just as important – consistent) it is, especially on the track. This means I can run distance or pace-defined repeats on any lane of the track, which lowers my stress level considerably early in the morning when there are often tons of people randomly walking any given lane.

    Bet you’ve seen this, but I think speed/distance accuracy is actually Stryd’s killer feature – and to me, without that, power training for middle distances is much more frustrating.

  51. Nedim

    IDK. Considering the differences between various running power systems and the technical difficulties, this all seems a bit pulled out of thin air. When two different manufacturers start producing similar results I’ll look again. Until then it’s “8:35/mile in run today”.

    Ray, would 2 people with similar weight running same pace by maybe different strides, have a similar result? Something to test – repeatably across athletes.

    • No, as running efficiency would impact things quite a bit potentially. Someone with the same weight could run faster with less power with a more efficient stride/form.

    • Aaron

      >>. When two different manufacturers start producing similar results I’ll look again. Until then it’s “8:35/mile in run today”.

      But why 8:35/mile? Why not 3.11888372 meters per second?

      I’m joking, but there is some fundamental truth – it’s less about the absolute value and more about what the “sensor” is measuring – the amount of work you’re putting out, which is a vastly different metric than speed. Two of the most important reasons to train with power (Jim Vance, Run With Power):

      1.A power meter can help you improve your running form by identifying the amount of energy you’re wasting on non-forward movements.
      2.Power quantifies intensity and eliminates other factors like weather, fatigue, and illness.

      Yes these are modeled metrics (a pile of caveats), but assuming the sensors are accurate and the variability low in different conditions, relative changes in your workout history will illuminate performance improvements, especially when combined with speed and heart-rate.

  52. Any hopes for Wahoo implementing something like this on the TICKR-X? IIRC you made a passing reference to Wahoo being capable of doing this when you wrote up one of your first running with power entries many moons ago. Got this post thru feedly as its not on the homepage, yet… did we break some kind of embargo?

    • Wahoo says they plan to implement HR-RD early next year in their TICKR straps, which would work with this.

      As for post not showing up on homepage, no, just an annoying issue that’s been happening in last 1-2 weeks that devs are trying to figure out. Comes and goes. :( I could have posted last Thursday on it…but alas, decided for catching up on sleep. ;)

  53. MAGNUS

    I just picked up a Stryd and I am quite happy with it. Like you noted, there’s no definitive way to validate accuracy, but it appears to measure consistently so I’m good with that… Not only that, it’s proven, at least to me, that it measures distance 99.9% accurately over multiple known distances/routes that I run. This helps increases confidence in its reading and results.

    But, had I known this was coming, I probably would have waited on the Stryd. Mostly because I own all three of the compatible Garmin straps.

    Also, side note, this post isn’t not available on your main page or blog link. Found it via Facebook.

  54. Nate C

    As an eager FeetMe backer who will likely be waiting at least a few more months (based on the lack of public announcements) to start running with power, this is bittersweet news. On one hand, I’m happy that I already have a 935 and hrm-run to try out the RunPow when it is released, but overall, I think we would all be better off if Garmin allowed the ant+ power profile to connect in running mode so that external devices could broadcast (calculated or force-measured) power and we could record and view all of the details (including 3s or 10s average, normalized power, intensity factor, lap power, etc) and analyze with all of the currently available tools/reports on Garmin connect/strava / etc.

    My worry is that because of their foray into RunPow with CIQ and lack of other announced/released actual power measurement device, Garmin is unlikely to “unlock” traditional power recording in the run app (since it does seem to be rather arbitrary that they allow certain sensors to connect in biking but not running).

    (FeetMe hasn’t actually even discussed publication whether they’ll have a CIQ app, or offer the option to broadcast in the bicycling ant+ power profile, so this is all still wishful thinking and speculation.)

    • In short, with the instantiation of a Running Power TWG, a running power ANT+ device profile could follow. That’s effectively force Garmin to implement it within their running watches. It’s really up to 3rd party companies to make this happen by kicking that ball fast and hard.

    • Joe

      Have you received any updates from FeetMe and what they’re struggling with? It’s early days for running power meters, but they seemed to have some promise.

  55. Jonathan Brown

    Hi there DC, love reading your reviews.

    Does this mean the Vicoaxrive 3 will get running metrics with the pod or HRM tri/run?

    • Via the Connect IQ app, it will/could.

    • Cam

      Hey Ray,

      Looking for a little clarity. You have said multiple times the VA3 could get running metrics via connect IQ app. The phrasing is throwing me off a bit.

      Does that mean the RD Pod will be able to connect directly to the VA3 during a run and display metrics, or you will have to have the app running/run metrics will only display after a workout is complete?

    • Indeed, it’s a bit tricky.

      So, the Vivoactive 3 (or any of the mid-range watches), won’t get the ability to magically pair to an RD pod/HRM-TRI/HRM-RUN natively in terms of Running Dynamics.

      However what’s happening is that Connect IQ in 2.40 gets the ability to pair via the HR-RD profile, which makes it easy for app developers to pair to those devices. It’s basically just like what you see for Muscle Oxygen and Cycling Power, and how you’ve got apps that support both of those across all devices these days. As part of 2.40 – FE-C is also added as a profile.

    • Neil Rosser

      OK so if the VA3 and RD-POD won’t pair natively, but seems the running/ground/contact, etc DATA can be made available to any app via the 2.4 SDK – does that mean that the cool dynamics data will be shown in the GCM app, post-run? Still seeking that answer – thanks.

  56. Einundsiebzig

    Thx Ray for that early insight. I totally agree with you, that a function like this belongs into the firmware of a watch.

    Any thoughts if Garmin power via pod also could be used for exact or lets say better pace than GPS provides? This is one big plus I see on the Stryd side…

  57. KK

    I lost interest when I got to the part which mention Fenix 3 is not supported…

  58. a

    Small typo:
    In any event – back to the run. As you run this power number will fluctuate just like Stryd’s does. Run harder, and it’ll go up, go up-hills and it’ll go up assuming *you’re* putting out more power.

  59. David

    A running power device nor supported by any running watches.

    That must mean there are.some new forerunners on the horizon!!

    • “nor supported by any running watches.”

      Umm…I listed exactly which watches it’s being supported on.

    • David C

      I assume he means any running specific Forerunners like the 235/630. Other than the Vivoactive 3 everything listed is what would be considered a triwatch. That said do you think that Garmin isn’t going to bother with running specific watches in the mid to high range anymore and just go with the triwatches?

  60. gingerneil

    Proper power support hopefully coming soon according to stryd….

    • Essentially they’re referring to creation of a Running Power TWG. It’d be in the interests of companies like RunScribe and others to join that.

      The dirty little secret is that if a TWG is created and a Running Power ANT+ Device Profile is instantiated, then Garmin is essentially forced to adopt it within their products. Garmin knows this of course, and isn’t opposed to it. The secondary secret is that if companies like Stryd or RunScribe go to ANT+ and say they need a profile by X date for Y product announcement, then ANT+ will usually nail that date at whatever speed is required.

      That’s precisely what Garmin does every time they announce a new category (i.e. radar, lights), as do other companies for numerous other cases – all of which usually have public ANT+ device profiles.. Non-Garmin companies essentially need to be more confident and learn how to work the system.

      If there’s any takeaway from Symposium this year (including things I haven’t posted about yet), it’s basically: You can no longer blame Garmin from a standards standpoint. For those that endured the rough livestream quality, I talk about some of these examples. Hopefully I’ll have the full non-crappy video stream up soon.

    • Oh, and as a casual reminder – at every ANT+ Symposium for about 6 years in my talk I have usually slammed Garmin on sandboxing standards and blocking 3rd party companies from leveraging advanced tech on their devices.

    • gingerneil

      Interesting… hopefully there is now enough groundswell for the various power brokers (see what I did there.. :) ) to get this moving.
      Were runscribe there at the symposium ?
      Is there any way for us mere mortals to track progress of a TWG, or do you have to be on the inside ?

    • No method to get into TWG’s. I’m not even allowed in those. Though, any ANT+ member can join a TWG (paying members only I believe, though for a company the cost is trivial).

      In the case of some of them, various members will usually tell me what’s going on. Or ANT+ themselves sometimes.

    • gingerneil

      They’re missing a trick there – I would have though that having someone like you as an indepedant ‘user’ view on some of this stuff would a huge asset. Although you’d need to invent a day with 30 hours in it!

    • Personally I’d love to sit and listen to some of it…

    • Adam

      So if we see a “Running Power” ANT+ profile implemented and the requirement for a CIQ app negated then *theoretically* could we see running power making it’s way to some of these older models such as the F3 and 920XT?

      Firmware updates for the F3 have been few and far between and the 920XT even worse, but that’s a tiny avenue of hope!

      I’m not too fussed either way because I think pace is a superior metric, but it’d be interesting to see how the numbers align.

    • The Fenix3 is out of firmware space, which is really why firmware updates have largely stalled. You’ll still continue (yes, really) to see some very minor tweaks, but it’s basically things where they can change a single line of code to fix/tweak something. Having talked to the dev team, the steps they’ve gone to, to try and find additional space is fairly mind-boggling.

      Obviously, it’s a situation only they got themselves into. But you have to remember that watch was basically in production over three years ago (with parts specified another 6-8 months prior). This was all before CIQ was even announced. At that point upper management at Garmin didn’t even believe CIQ would be a valid long term avenue. It was mostly viewed as a cute experiment.

      Things are much different now of course (especially within management), but sometimes it’s hard to turn on the way-back clock and remember how the world was.

    • Steven Shaw

      Maybe they could dump all the golf stuff and that thing that electrocutes dogs.

    • Michael B.

      Interesting. This has been a bone of contention with me. I have been a Garmin watch user for running since the original 2xx watch. Most have been buggy and failed within a year or so. But I haven’t found a good alternative. I currently have a Fenix 3HR and have been happy with the watch overall, and unlike other Garmin’s (fingers crossed here!!!), it is still working!! But, I have been quite unhappy that they so quickly stopped supporting it with upgrades. Do I understand you correctly that this is just bad luck due to the ConnectIQ situation, and future Fenix watches will not become obsolete in terms of upgrades so quickly? If so, I am bummed about no upgrades, but a little less unhappy with Garmin overall.

  61. blazko

    For some reason this post won’t show up from the blog view… I could only find it via a link on Stryd forum. Is this a error?
    Great news, BTW

  62. Just trying to get my head around this 100-150W difference in powers.

    Why are the elevations (Y axis) in the Garmin and Stryd plots so different?? Are they not from the same terrain?

    Overlaying the two images is a 2 minute job on the computer but not with the axis values so off, make them comparable.

    Another way to overlay would be to just print out the two pages on identical scaling on A4 paper landscape , hold them against the sunlight. Old school but works.


    • As noted in the post, I didn’t have control over the screenshots on the Garmin side, because they were done on Garmin’s internal beta servers. As noted I sent them my file and they sent me back a pile of screenshots.

      Still, it really doesn’t matter in this case, it’s very easy to look and see they are offset by 100-150w. Certainly it would have been my preference to have both data sets shown, but that wasn’t in the realm of possible this time.

  63. Kaz911

    Great more focus on Power :)

    But what I really want from Garmin is their performance tracking and implementation of FirstBeat data to be extended to indoor use as well. So according to FirstBeat treadmill running is fine for providing form power data – Garmin does not implement it since they obviously does not trust their own speed sources on a treadmill. FirstBeat data calculations are obviously dependent on reliable speed detection.

    But with Stryd foot pod – I have close to perfect tracking of speed on treadmill. Much better than GPS speed in any case. So now VO2max and training effect could easily be implemented for indoor activities. Same goes for indoor cycling with power meters – which FirstBeat algorithms supports but I still think Garmin does not.

    But maybe run power from Garmin is first step towards full implementation of FirstBeat Algo’s.

    • You’ll see more/better integration of FirstBeat going into Q1 2018, mostly on the backend for things like cross-device sync between multiple devices (Edge/Vivo/Fenix/Forerunner), as well as site/app surfacing of that information.

      You’re starting to slowly see things. Garmin is keenly aware of the gap here and looking to remedy. As they themselves noted ‘it’s impacting our best customers’. It won’t be a switch overnight, but you’ll just start seeing the individual gaps be filled one at a time.

      Of course, doesn’t really answer your indoor question…but seemed like a good place to stick it. ;)

    • RodgerT

      That’s some of the best news I’ve heard. My Vo2Max has been screwed up for the last couple of weeks after adding a Vivoactive 3 which had to “learn” me so the graph bounces between 48 and 53 depending on whether my last run was done with it or my 735.

    • kaz911

      :) Garmins footpod generally is not very good on treadmills as they even with calibration tends to drift. Especially as you get better at running you need to keep re-calibrating. I NEVER have that issue with my Stryd sensor(s). And at lower speed < 7km/h Stryd is much better than Garmin but still not perfect.

      But since I have run outdoors for a bit in Spain – I was surprised how bad GPS really is for speed/distance (Fenix 5x) if you run among buildings even only 3-4 story ones.

      One day my Stryd did not connect and I found out the hard way about how bad GPS is :) I could not understand why my pace was at 7:39/km as my feeling was around 6:20 6:30/km – after a few minutes the right pace came back to around 6:20. When I looked at the log – i found out GPS had cut a lot of corners and I lost about 600m on a 9km run.

      Next run with Stryd as distance measure – run distance was back at 9km within about 50 meters of the other runs of the same route.

      Garmin should just buy Stryd and get it over with.

      I'm not affiliated but backed kickstarter – upgraded to Footpod.I did not like the chest strap Stryd very much but the Stryd foot-pod is like my Apple AirPods – they are my favourite low weight running gadgets :)

  64. Struan Lownie

    I’m not seeing this article on the site, either on the home page or under product reviews. Thought I was going crazy till I scrolled back through Twitter and found the link

  65. Garry Curley

    Okay, that is pretty cool.

    I can see this being the next sensor automatically baked into the watch. I wonder how much real world use this will offer runners? Certainly worth playing with for sure.

  66. Richard McDowell

    Heads up – minor typo in the first sentence, seen instead of soon.

    Cheers, Rich

  67. So—Fenix 3—what hope is there with getting running power onto this watch? Waiting for a developer to make an app – because Garmin isn’t? Is that basically it? Or it won’t be able to do the equivalent; ever?

  68. DerLordBS

    I am living in a flat area. The next mountain is 45 minutes by bike away. I virtually ever do running on a flat area. Does it makes any sense to mesure power instead of speed on a flat run?

    • JR

      Theoretically you can use power to determine efficiency (watts per speed). You could track long-term improvements in efficiency as well as the breakdown in efficiency that occurs late in hard workouts or races. On the other hand, you can pretty much do that right now with running dynamics. GCT is a pretty good indicator of your relative efficiency over long periods of time, and all of your running dynamics metrics will tend to get crazy at the end of really hard efforts (even if pace stays the same).

    • Paul S.

      I don’t know how it is with runners, but as a cyclist you can easily tell the difference between a warm, windless, day and a cold, windy day on the exact same course. It’s harder in the latter case, and will show up in power numbers. Or suppose you did go to the mountains to run. Then your power numbers would tell you if you’re making the same effort as in the flats even if you do go slower on average.

      The question here is whether the numbers are “right” or not and what they mean. Cycling is much easier to figure out, because there are no short impacts with a foot covered with elastomer going on.

    • Tim Grose

      Current running power meters (OK the Stryd at this time) are nothing like bike ones that measure direct force. From my experience of a Stryd it does not model the wind or the terrain at all. Witness a test running both ways on a beach for the same RPE. Around 100W difference so useless in that environment which would be one great place to use it. In theory, if it could model the effect of wind then it could be very useful in a flat location.

  69. TVDW

    This is bullshit, I have a Fenix 3 and a 735xt. Not planning on buying another high end watch only to loose updates after a year.

    Let’s hope Wahoo goes into the running watch business.

    • The FR735XT simply doesn’t have a barometric altimeter. There’s really no getting around that requirement.

      As noted previously, the Fenix3 was the first of two Connect IQ watches out there, and Garmin simply ran out of space there on updates and processing overhead. It seems like they’ve learned a fair bit there – but being the first watches in the 3rd party platform pipeline almost three years ago meant that they hadn’t quite learned all their lessons yet.

    • JR

      It’s one thing to complain about a company that stops supporting its products and fixing bugs, but I don’t understand why people purchase products knowing their capabilities and then get upset years later when the manufacturer doesn’t provide free upgrades–leaving aside the distressing trend of companies introducing incomplete products and promising future features that should have been there to begin with.

    • Tim Grose

      Agreed JR. Anyway Wahoo is a bad example as, for instance, you will need to buy the new Kickr if also want to add the Kickr Climb when it comes out. That was seemingly done for similar reasons to here – the older ones just were not able to support it on hardware grounds. Also, I mentioned elsewhere, the 3HR got a new beta the other day.

  70. Rob

    I’m sort of surprised that a pod on your shorts would have more ‘power’ than one on your feet.

    Can you wear the Garmin pod on your shoe and see how the numbers change?

    Just makes more sense to me that your foot/ankle is where where power is coming from but maybe I’m “locked” into that paradigm since I’ve had footpods for 20+ years.

    You mentioned that the Garmin RD pod does not give you speed/distance even though it can measure it (via an accelerometre). That seems to be one metric that helps tie into power that can be measured, both indoors and outdoors. Would be nice to have.

    As I own a stryd pod, I have always seen the speed and distance #s to be better than Garmin’s. Usually close though.

  71. Henning

    Quick question regarding the avg. power in the split overview. I am using Stryd and was looking for that information a couple of weeks ago. I rechecked today after I read your article and the avg. does not show with Stryd. Is there any way to activate it or does it require a different version of Garmin connect for Stryd to show in the split overview?

  72. “CIQ fields can’t be used as intensity target” – this is the thing that sucks the most, in my opinion.

    For what it’s worth, Stryd have worked around this with a Connect IQ app (PowerRace) which allows you to dial in a target power and it then beeps and vibrates if you go outside of the target zone. That’s fine for runs where you’re trying to maintain a steady effort, but it’s not very helpful for structured training (eg you can’t tell it you’re going to run 5 minute repeats at Z5 with 1 minute recoveries). I guess a workaround is to carry two watches …

  73. Andrew

    Hello Ray,

    From a completely Subjective perspective. Watching the two different power numbers during your run and looking at the data after the run (Stryd smoothing vs Garmin). Which one of the two feels more like it matches or visually represents your RPE. Or provides more actionable data both in run and post run?

    I think that is the catch to bring a metric like this to the masses, or to make it a really awesome game changing break through for training and racing. Data is always cool, but to be able to briefly glance down at your watch while climbing that rocky trail in the middle of a race, or tempo session and adjust accordingly and confidently is hopefully the end goal.

    I kinda hope someone will whip up an algorithm that combines things like vertical speed/pace/heart rate/power and spits out a 1-5 or 1-10 number to train and race by.. should be simple right :)

    Anyway, Does one Feel more usable to you currently?


  74. Tim Grose

    I’ve given a power a go on the Stryd for some months now but TBH not sure it has ever got past a view point of “interesting” – here is another number to look at. Running is quite different from saying cycling in that if you run uphill you largely do it one way whereas on the bike you can grind, spin or somewhere in the middle and get up the hill at the same speed but maybe not the same effort. Power there valuable to analyse those differences. I see a lot of comments from Stryd users that it makes for a great foot pod and so gives me a far better instance pace than say GPS which I don’t disagree with and yet for maximum usage of power, you should not really care what your pace is but, of course, to runners it does and hard to think it won’t suddenly. Then there is the also question of product endorsement and how it is being used at elite levels. In cycling stuff like GCN is daily telling you what the pros do and implying it could help you too. You never really get that in running and, no disrepect intended, I don’t think I have heard of any of the runners Stryd mention as avid users of their product.

  75. Thomas DJ

    Looking forward to your experience with the Arion’s!
    Been testing them for a while too. From a technical viewpoint, the Arion’s sure sound more trustworthy. With measurements on both feet and spread all across your insole.

    Though I can’t get my head around all the data just yet. There’s so much of it and no easy way to interpret them yet.
    And of course, the main drawback that it requires your phone (at the moment).

  76. This makes a lot of sense to me. Traditionally sensors have processed their data internally and sent completed metrics to the watch. That was sensible back when battery life/processor power in the watch was an issue. Times have changed though. We now have watches with more processing power than we need, battery life that’s fine, and more data points to work with.
    It seems like the next big change for these devices should be to receive more raw and high definition information from a sensor to allow the watch to decide how to work with that information, or even just store it for a computer to later use. HR data sent once a second is nice, but ECG straps receive constant analog information which could be digitized and recorded, allowing for various stats to be created alongside more medical uses. Power is obviously a great catalyst because it doesn’t justify a new sensor, just needs interpretation of sensor data already available. This will ultimately need a complete overhaul of the system and lead to data feeds (aka properly raw sensor information) and a structured way to build that into stats including some kind of “relies on” ordering for building up information from data.
    The question then changes from “is the power accurate” to “is the VO feed accurate”. We’re already at a state where lots of assumptions are made. VO isn’t measured directly, and neither is pace, so any power data will naturally have a wide margin for error. I can see cycle power meters moving from sending a current power ticker to streaming strain gauge data in real time within a couple of years too. Interestingly that would then free us to use a Stages algorithm with PowerTap strain gauge data, opening up a whole new market for algorithms while potentially lowering device costs. It would also give researchers much, much more rich data if the high def streaming happens.

    • Eli

      Dave, you’re missing a big part of this. Its not just processing power, its the amount of data too. The amount of raw data from sensors is very large and is filtered down to broadcast over Ant or BLE that saves lots of power on its own. Why do you think Ant/BLE take up so much less power then wifi?

      The fact that many of these sensors use specialized processing and not general purpose processors saves processing too. Watches still don’t have that much general purpose computing power to make up for that.

    • Not missing that at all. Some data needs to be small and real time and some doesn’t. Also, bandwidth available in modern BTLE is way more than was available when HR tickers were first created. Store and forward is also a thing though, so there’s no reason post processing couldn’t be used to augment what was available during a run. The important thing right now that any data scientist will tell you is that you need to capture all of the data.

  77. The Real Bob

    I wonder if the pace of these advancements are going to lead to fitness devices being like phones. Meaning, most people probably upgrade their phone every 2 years. ( I don’t, but I am sure most do)

    Are we moving into the realm where I will be replacing my 935, which I just bought, in a year because it won’t have the capable hardware (see 920xt) to support the software.

    We live in exciting times.

    • Tim Grose

      In recent years I have swopped Garmins (920, then 735, now 935) quicker than my iPhone 6S! In reality there is not a massive reason to do so as 95% of the time it is the GPS distance/pace, stopwatch time and HR info I look at the most and that bit is pretty much unchanged. Then again maybe now I am “happy” with a 2 year old phone as I now don’t always need to pull it out to show me what messages have received.

  78. Crispin E.

    I can’t see that anyone else has already asked this (so please forgive me if I’ve missed it), but would having a foot pod paired with to the the Garmin give RunPow a less ‘noisy’ output, more in line with Stryd? Given that instant pace must be a significant component of a power calculation, it follows that foot pod pace would result in a better calculated power than that calculated from the more noisy GPS derived instant pace. I note that in the video you mention that both the watches recording RunPow and Stryd are set to GPS pace, but of course Stryd is already calculating pace onboard the pod and not relying on the pace data from the watch to calculate the Stryd power.

    Another related question that I haven’t seen answered; does RunPow work with indoor running? (so using watch accelerometer or foot pod pace instead of GPS)

    • Tim Grose

      I recall Stryd saying that pace is not directly used to compute power as when they were fiddling with their algorithms to avoid “calibrating” the thing for current pace then they said that this should not effect the power numbers. After all if power was mainly a function of pace offset by the current grade of where you are running then in most cases they would be little point as unless terrain is particularly hilly pace when running is way more consistent than it is when cycling. OK it seems VO is included but that seems pretty consistent within my runs. That all said power is highly likely to go up when you go faster assuming all other factors are the same.

    • Crispin E.

      Thanks Tim. Interesting that instant pace is not ditectly used in Stryd. I’m still wondering if the Garmin RunPow does use pace though and if it works indoors.

      I’m waiting on delivery of my RunScribe Plus units to answer the question if they have a barometric altimeter or if they use another way to calculate that element of the power equation. There’s no theoretical reason why accelerometers couldn’t calculate the height difference between steps, which would give you instant grade change; arguably better than barometer derived grade for instant power calculation perhaps?

    • Paul S.

      Well sure there is. Accelerometers that fit in pods and watches are just not that accurate. Noise and error will soon overwhelm accuracy. Barometric altimeters have a precision of a meter or less.

      If perfect accelerometers were available, Garmin and the others wouldn’t have to bother with GPS. Just integrate the equations of motion, and you’d know exactly where you were and at what velocity. Nuclear submarines do this to high accuracy from what I’ve read, but the captain or navigator don’t wear the accelerometer on their wrists.

    • Crispin E.

      But those same ‘crummy’ accelerometers in current foot pods already measure stride length (the horizontal) to a surprising degree of accuracy; so why would it not be reasonable to assume they couldn’t do the same with the vertical. Cummulative errors over time might make them not suitable for tracking absolute elevation changes over the course of an activity, but surely it’s the short term elevation change over a few strides that’s relevant to a power computation. With the second generation of pod sensors (Stryd and RunScribe Plus) having far superior sensors to the old Garmin ones, plus computing readings hundreds of times a second (500Hz for RunScribe Plus), I don’t see them reliably deriving altitude change from the accelerometers as implausible.

    • Tim Grose

      They do measure vertical oscillation however which clearly is a factor in the power calculations as Ray notes.

    • JR

      I’m actually surprised that a barometer is a useful way of measuring incline for power purposes. I could see it working over very even inclines, with a fair bit of smoothing, but it seems like it would have a lot of limitations. But what do I know!

      Incidentally, I haven’t received a shipping notification from Runscribe, so I was wondering: (1) when you placed your order and (2) whether you registered an account with Runscribe’s online store, or just checked out as a guest. (I did guest checkout and can’t sign in to check order status, but I did get a confirmation when I placed it.)

    • Paul S.

      Barometers are not very good at it. Just look at the slope number from any Edge. They generally lag and oscillate a little. They have to take the ratio of two numbers, both containing error. For power purposes, I’d assume you’d ideally want a digital inclinometer of some sort, but not in a pod tied to your shoes. I don’t know what’s used in my Velocomp PowerPod, but the incline numbers generally look reasonable, if a little noisy (then when it counts I’m usually ascending/descending gravel roads or worse). It has a barometer, and is paired to the speed sensor, but I don’t know if they use that for incline or not.

    • Zoltan

      I see you have some experience with Velocomp products. I sont know much about Powerpod, but I have a Newton+ and its tilt measure (incline number) is quite perfect.

      It has some sort of accelerometer inside, because it filters out the acceleration of the bike itself measuring the differences in your speed. I know it very well, because at lower speeds the titl number starts to fluctuate. What I did was the application of five magnets put on spokes in an evenly distributed way (20h rim) and the accuracy is still OK even when I climb on 20% at 4-5 km/h

  79. Eli

    For running dynamics being a Ant+ profile:
    link to thisisant.com

    I still don’t see the standard on their web site:
    link to thisisant.com

  80. Mike LaChapelle

    Ray, why do they use a barometer-equipped watch to determine whether you are ascending or descending? Wouldn’t the altitude reading from the GPS be much more accurate than barometric pressure?

    • Nah, GPS altitude is more complex to derive and can be easily impacted/tricked on a short-term basis. While baro altimeters have their own set of issues, it’s a more predictable set of issues to deal with.

      Some companies do non-baro better than others. In general, I see Suunto doing a very good job with GPS elevation data, whereas I see Garmin as less awesome (example: My 1-year old would draw a better elevation graph of a flat run with a spatula of Nutella, than the FR735XT would).

  81. JEROME

    What as see as main difference in data given by Garmin HRM running dynamics RD versus Stryd developer data is the vertical oscillation (in cm). If, for both, Ground Contact time GCT are exactly the same (to few ms), Garmin HRM RD gives (for me), in average, 35% more of VO than Stryd (7,2cm vs 5,4cm on flat).
    I would say that VO is more accurate for Garmin HRM RD as the chest trap is closer to your center of gravity than the Stryd footpod! This might (partially) explain the difference in running power between Garmin and Stryd (> more work is necessary to move vertically my (heavy) mass as E= mgh).

    • Hi Jerome,

      Disclaimer: I am with Stryd.

      Measuring run dynamics from sensors clipped to elastic bands in shorts presents challenges to providing day-by-day consistency. It boils down to changes in mechanical coupling of the sensor pod with the core body’s motion.

      There are three main contributors to this issue:
      1. *Consistency of affixing the sensor to the body.* On the shorts, the materials and construction of each pair of shorts or pants you wear will vary the sensor pod motion data. For example, with looser waistbands, the sensor pod will be free to “flop” a bit more on your back, introducing extraneous motion data into the sensor pod. In the case of the chest, the strap does a relatively better job of keeping the sensor mechanically coupled to your chest skin, but chest skin unfortunately also moves independently to core body motion, which leads us to the next issue..

      2. *Consistency of body composition.* The sensor pod is coupled to (moves with) skin or clothing, not your core body movement. As you gain or lose fitness, your body composition (i.e., fat and muscle thickness) behind your skin changes, and the sensor pod slides around more or less on top of the core body’s motion, reflecting it more or less. The problem can be particularly bad due gluteus muscle contraction movements, with bigger backsides adding especially significant extraneous motion.

      3. *Consistency of the sensor’s relative positioning on the body.* Some pants or shorts waistlines naturally ride higher or lower on your body, and with reclipping the sensor to them each day, day-by-day the sensor positioning could be moving up, down, left or right relative to your own anatomical features. As mentioned above, especially problematic is the position of the sensor relative to the proximity to your gluteus muscles, which move up and down independently of your core body when running. This, and also the movement of more or less fatty areas of skin, will introduce extra movements into the sensor signals and their readings.

      We noticed this with Stryd’s first generation chest strap, and we specifically addressed the skin and fat layer on the chest by having users perform a skin calibration through a baseline test. While this works, it is not possible to do from the shorts, since you would minimally need to perform such calibration for each pair of shorts or pants you run with.

      Angus & the Stryd Team

    • JEROME

      Thanks Angus for your comment but I don’t wear my footpod on my short :-)!
      I was just comparing VO given from running dynamics with my HRM-RUN (worn and firmly attached on my chest) with VO given by Stryd foodpod (worn on my shoe) : +35% in average +1,8cm (VO Garmin/ VO Stryd)
      Comparing GCT the difference is only -5% in average -12ms (GCT Garmin/ GCT Stryd).
      I don’t know if this comparison is correlated for others with different weight, size and …shape!

  82. jelin11

    I am currently using stryd with my 935. I will receive RunScribe plus (which also supports Power) soon. Once Garmin release the new CIQ field. I will have 3 power sources. How many will I be able to use in a same run?

    2? per the limitation of 2 max CIQ fields?


  83. Jason C.

    Ray – two quick questions:
    a) How would the Stryd and Garmin variants compare to the power read-outs on most treadmills? Have you been able to test this?
    b) Generally, how does “running power” output compare to “cycling power” in terms of perceived effort – if that’s at all possible to determine with any certainty? i.e. Does a 300 W avg run feel similar (HR, breathing rate, etc.) to a 300 W avg bike? I realize there will no doubt be a tonne of variable and factors at play here.

    • Tim Grose

      With Stryd their app allows you to input the current incline of the treadmill and it adjusts the power numbers accordingly – thus a bit of a fudge. You can’t do that with a Garmin or other watch though AFAIK. I recall they maybe be working on this but otherwise when I last tried it cannot “natively” detect the treadmill incline. Have you seen a treadmill that gives a power reading?
      For me with a Stryd and a bike power meter then 300W is both hard. It’s around my bike FTP and I was getting just a bit higher (say 330W) in all out 10K running road races. The numbers won’t obviously match up exactly but at least it made some logical equivalence. That said 200W on the bike requires a decent amount of spinning effort but I don’t think I was able to run slow enough to see under 200W running so it was definitely a bit higher running but I like to think I am a better runner than cyclist. The Garmin power numbers appear to blow away any comparison however…

  84. Allan Saito

    I’m a Stryd user for around 3 or 4 weeks now. I saw that your power data on garmin is considerably higher than on stryd on the same run.

  85. Jeroen V

    Interesting read:

    Why only 2 CIQ data fields? ( even on my fenix 5x, should have enough memory)

    What is the golden standard for running power validation ? How( and in what population/conditions) do Garmin and stryd validate their numbers ( Same question for other ‘smart’ numbers like Lactate Treshold, v02max, etc). IMHO: no golden standard, no well defined validation –> useless in any advanced athletic situation.

    • Tim Grose

      LT & VO2 Max is “easy” – plenty of places offer direct measurement of it running on a treadmill whilst measuring your actual oxygen uptake and lactate levels until you pretty much literally fall off the back in the all out effort. I did one as long ago as 1995 and it was hardly “new” then. Much less clear on power but clearly Stryd and Garmin have attempted to do so although appear to have come out with completely different results! Will be interesting to see if the Garmin numbers come down to nearer the Stryd ones as this develops…

    • Su-Chong Lim

      @Jeroen V: You are absolutely right. There is no accepted standard. Running Power may seem like a simple straightforward entity, but it’s pretty nebulous, because you can’t measure it directly, like you can by measuring force at various points on a mechanical drive train on a bike. So, while Bike Power can be accurate precise and reproducible, and can be used effectively to monitor output during a race, without worrying about transient changes in efficiency throwing you off (I’m talking about direct force PMs here, not the back calculation PowerPod type), these Mickey Mouse derived running “Power” values based upon back calculations and mean algorithm estimations can have no practical use, at least, not in their current vision. (If you mean they can be useful as a proxy for real intensity of effort for a given individual, I’ll give you that — but then call it for what it is).

      Actually, you can get a pretty accurate lab estimate of a runner’s power expenditure on a treadmill by measuring VO2/t (consumption) and VCO2/t (production) under a given set of conditions, and calculating the fuel energy consumed per unit time. But you have at best a hazy idea of the running efficiency, so, then, what is the effective power output (and how you would define it) is anybody’s guess. Coming back to applying that real data via some back tested algorithm to your live road runner whose cadence, velocity, mass, and rate of climb (and maybe foot-strike duration, foot trajectory path…?) is known or is being measured, by micro-tabulating all the forces on shoes in different vectors in millisecond bites — c’mon, now; just because you have the computing power to do it doesn’t negate the lack of precision, let alone lack of scientific rigour in your results and postulations.

      I think now of the supposed VO2max calculators when they first came out and I am reminded of what I thought at the time — this is bad, the consumers with superficial theoretical knowledge of VO2max terminology will take them seriously, and now there’ll be a whole spawn of nonsense consumer metrics being trotted out…boy was I right.

    • Su-Chong Lim

      (sorry about the careless bolding, I missed an “unbold” statement, branding me forever as an internet rookie, and/or a boor ‘cos I can’t fix it.

  86. Jonathan Keeth

    Bad show Garmin! Not updating this to older units like my 18 month old 3hr would be like if Apple said they would no longer support updates to the iPhone 7 now that the iPhone 8 is out. I got really excited by this article when I saw the headline (you did a great job as always Ray) but as I learned that I would need to upgrade a practically new watch to get this function, the more frustrated I became. Oh well, silly me for thinking a $550 (at the time) watch would be regularly updated for a while.

    • Sandro

      You are in good company, if that’s any relief. And there’s worse than owning a Fenix 3 in terms of obsolescence and support, even in the Garmin world (Epix owner here…)

    • Tim Grose

      Obviously I can understand the frustration but I see the 3HR got a beta release only the other day link to www8.garmin.com
      The iPhone analogy is interesting because older models cannot take an iOS update to the latest version and obviously say my current 6S has lower specification hardware than the current model. On the other hand it still works largely as good as the day I got it for what I really want to do with it at the time of purchase. Then you could say drat if you bought an Apple Watch a few months and now, for similar price, the new model can make and take calls…

    • okrunner

      To add insult to injury the older 520 can accept it, it’s older and it costs half as much as the 3HR. But then again, I have a tempe pod, cadence footpod, and a milestone pod (for treadmill zwift) on my shoes. Starting to look a little weird with all these pods and I certainly don’t understand power for running anyway.

    • Jonathan Keeth

      Good point Tim. Thanks for the link to the beta.

  87. It’s a very interesting question about the relative power of different activities. I have a Stryd footpod (running), a Stages meter (biking) and a Concept2 rower (indoor rowing). All report ridiculously different wattage numbers for the same perceived level of effort. I was cool between biking and rowing, but am flummoxed at how Stryd has about 15% more watts running than Stages has for biking for the same perceived LoE (and even measured heart rate). Garmin going “full gonzo” and having 50% more jis giving me a headache.

    My number one use for power is to have a gauge of how hard I’m working that’s independent of wind, grade, etc. I try and maintain set power levels (running or biking) for a given period of time. Later, it’s interesting to look at correlations between HR and power, and power spent on the same routes, etc. Figuring out how to map power measurements across sports would be helpful in tracking how efficient my body is over time. This appears to be a very difficult thing to achieve… as evidenced by Strava banishing running power — it was messing up the power curves (where watts are watts).

    Or do I have this all wrong?

    • Tim Grose

      I was finding Stryd running power and bike power certainly in the same ballpark. For me running was about 10% higher say comparing 20-30 min all out effort levels but I am (when not injured) a better runner than cyclist. This article suggests the Garmin numbers are way higher. I guess it does not really matter as long as the readings are consistent run to run. Yeah the Strava power curve thing was annoying as my best readings were coming when running but only in a short window when those runs were included.

    • Aaron

      Ahh, wait until they have power for swimming too. :)

      Power curves need to be aggregated and compared by sport. You shouldn’t have a single power curve that has a mix of data coming from running, cycling and … whatever.

      I don’t use Strava, do they not separate out their power statistics and “best of” efforts by sport?

    • Adam

      Why would you expect your perceived level of exertion to match power output over three different sports?

      They’re wildly different biomechanical actions involving completely different muscle groups and completely different biomechanical efficiencies. Whilst your RPE *may* correlate well with something like VO2 uptake or heart rate across disciplines (although that’s not a given) there’s no reason that should correlate closely with functional power output.

      What you’re searching for might make life easier in computing these numbers, but in my opinion it’s based on the fundamentally flawed assumption that input is proportional to output across disciplines.

    • Su-Chong Lim

      @Aaron: in swimming efficiency in humans is firstly a miniscule percentage of energy expended (3 to 9 percent by one estimate), hugely dependant on technique, varies immensely across different individuals, and, given proper instruction and rigorously applied practice, can change markedly in the same individual over time (think Total Immersion swimming instruction as one disruptive example). So any technology deriving Swimming Power from water density, stroke rate, stroke distance and mean (or even micro-calibrated) velocity etc., is in big trouble from the start, even more so than Running Power, which, admittedly, can be hard to envisage.

    • Aaron

      Nah, it will be a direct measurement system for sure, probably in a hand glove of some kind. Wouldn’t that make more sense?

    • Paul S

      I thought power in swimming, like almost everything else, comes mostly from the legs?

    • Su-Chong Lim

      Legs are more powerful, but how they are anatomically shaped (optimized for terrestial efficiency) makes them horrible for swimming efficiency. Most effective swimming propulsive force comes from arm movement.

    • the5krunner

      hmmm. one of those Suunto developer pods (movesense)…that might just do the trick. someone shoudl think of doing that and integrating into swim paddles. …

      or maybe they already have.

  88. Brent

    Hey Ray, for cycling I use a power meter to give me a closer measure of how many calories I am burning versus relying on heart rate or just the normal calculation(which is typically way off)

    I was looking at your screen shot and it seemed that calories burned seemed to be pretty high 1500 calories for a 7 or 8 mile run. Do you think running power has the potential to give you pretty good idea of what your calories burned similar to what power meters for bike do. I generally I assume for me it is a little over 100 calories per mile which is what the garmin fenix 5 gives me when I am using a heart rate monitor.

  89. Ben

    I’m mainly a cyclist but I occasionally run. I fully understand power and powermeters in cycling terms but this is the first time Ive heard power mentioned in running.
    Can someone explain it to me please? Is running power the same principle as cycling… Where you have your FTP baseline and then training zones are based on a percentage of this (active recovery zone, endurance, tempo, threshold, vo2, anaerobic, etc etc)? Also cycling power is useful for used for pacing endurance events or time trials (if you know what you can sustain) and afterwards it will show you the intensity of your workout, taking gradient and wind into account and can be used to gauge fitness and freshness.

    • Aaron

      Jim Vance’s book Run with Power is the current authority on the subject. We did a review of it and covered the main points on our blog: link to sporttracks.mobi

      Don’t be scared by the page count. The bulk of the book is training plans – as far as the “meat” goes, its probably a 60 page read if you’re already up to speed on cycling power.

      The biggest difference is that in cycling your power is transferred through a mechanical linkage to generate forward movement, power mostly measures fitness level, whereas in running it’s all happening biomechanically, which means measuring forward power can (in theory) illuminate inefficiencies in your running form in addition to fitness level.

  90. DT


    As always, great post!! Thank you for that.
    Two unrelated questions:
    1. I have a stryd and I think their app is painful. I guess Garmin should do better, right? and
    2. I know you love the scoshe and so do I but doing a 70.3 with it doesn’t work. I have a Chronos. Which HR monitor would you recommend for a long race that is not a chest strap and won’t fall when swimming, etc. Would Mio Slice work? Thanks and regards

  91. Garmin just made itself a competitor to Stryd

  92. Mike Richie

    You know, Garmin COULD have fixed many of the limitations that you covered and still stayed within the Connect IQ framework (still can). They could create a data field that was raw power for inclusion in the FIT file and another data field that was essentially a multivalue data field (that works as a data page on a single field page) that could display current power, 3 sec, or 5 sec and Avg power or Lap power as well as a couple of other configurable fields. They could also make a power graph field the same way. In addition they could make an CIQ App that was essentially a paired down run app that could allow all the power fields as well as power alerts and lap summaries. (It could still write the power to the FIT file). The additional code for these “display” methodologies is probably already written, somewhere at Garmin, and the real programming challenge is in the power algorithm. By the way, Stryd could do something like this as well, surprised they haven’t.
    That being said, I do think it is good for Garmin to see the limitations of their current CIQ data field setup, and if it leads to them expanding the number of CIQ data fields allowable and allowing a system for data fields to be used in alerts, workouts and pop up summary screens, that would be the best outcome. This is where Garmin needs to innovate to differentiate itself from Apple and Fitbit.

    • gingerneil

      Maybe.. maybe not. I’m not sure if a field can output its value as the input to another CIQ field – so every one of the fields would need to compute power from the raw data. If the power data needs to be calculated by more than one field at a time (or more than one element of a large multi field page), the processing power of the watch could soon come under question. I dont know how much grunt the watch is using to compute and display just one power field – could it cope with 3/4/5 ?

    • Note: Garmin says the data field will have some GCM configurable items like Stryd does.

    • Mike Richie

      Fairly complex calculations take surprisingly little time in modern CPUs (even on a watch). (Think about the complex calculations done for every pixel in an HD image at 30 or more times per second. That’s not exactly equivalent and using a GPU, but you get what I mean.) Even so, a local storage area could be used to write a timestamp and raw power calculation that could be calculated and accessed by any of the fields if that became necessary. I’m sure Garmin’s calculating power and storage capabilities will increase apace. Apple now has a surprising amount of the iOS API available in WatchOS.

  93. In other news, Pauley Perrette is leaving NCIS at the end of the current season. ☹️

  94. Hi All-

    Just as a quick update, per some of the requests in the comments here, Garmin has provided a slide/listing on all of the scientific papers they are using as the foundation for their algorithms.

    Additionally, they also provided a secondary slide on their thinking of native vs CIQ app. There’s a much longer explanation of how that slide cam to be in my added text above.

    You can find a whole ‘update’ chunk just above the final section (quick link here, then scroll up to see it: link to dcrainmaker.com)

    Note: Garmin was not asking for either slide to be published, rather, I asked them if I could get them published, since so many folks here seemed interested in it.


    • Markus

      Thanks for the update.

      However, all Garmin can show is a list of references? Even I could have pulled up the list within a few minutes on pubmed. I’d be more interested in the validation of their approach.

  95. Hi All,

    Disclaimer: I am with Stryd

    Watch this example video to see how Stryd verifies power outdoors: https://www.youtube.com/watch?v=8BiBkmxIVNQ

    Running power and metabolic cost have a well established relationship. Therefore, metabolic cost has been used to validate running power technology. As a matter of fact, running efficiency for most runners is below 25% (link to storage.googleapis.com). Elite runners may be able to approach 25%. Matt’s outdoor test shows his average power is 344 watts with a VO2 of 72.6 ml/kg/min (link to blog.stryd.com). This translates to a running efficiency of 23.5%. If you assume power deviates from Stryd by even an increase of 100 watts, that means efficiency is beyond 40%.

    Angus & the Stryd Team

    • Mike Richie

      Not to be picky, but the conclusion that running efficiency (or ME, mechanical efficiency) in the article referenced was less then 25% or approaching 25% in elite runners was based on testing using Stryd power figures, therefore it is meaningless to compare it to figures produced by a different method of calculating running power as you appear to do in your last sentence.

    • Adam

      Do you guys have a link to the other three papers mentioned in the introduction of the “Physiological differences between trained and untrained runners” paper?

      I’d be interested to have a read. Many thanks!

    • Su-Chong Lim

      I think this should give a heads up to everyone who thinks running power (e.g. as presented in a back calculated real time metric in a running watch) should be taken seriously at face value. Metabolic cost can be measured in a lab to a reasonable degree of precision. But when the estimated efficiency of running is as low as 25%, the precision of the back calculated power output in watts at any random moment, or even over several seconds has to be questionable. If this calculated value purports to be a surrogate number that more closely matches actual output than some measure of perceived level of exertion e.g. the Borg RPE scale, fair enough, but then say so, and prove that this is actually so. If this claim actually holds up, then we may have a useful metric for monitoring training and race intensity. But this exercise in sophistry and displaying the result in real-time watts risks (or maybe is intended to) confusing the consumer who is used to seeing cycling watts displayed and using these values to predict or control training and racing strategies and outcomes.

    • Interesting comment on ‘precision’ of back-calculated power. IMU, I’m not sure if they are back-calculating power from the efficiency, what made you think so? It would be irresponsible to take one person’s mechanical efficiency and apply it to thousands of users across the board. The actual value of training an elite athlete with such a model will be extremely questionable. Therefore, I do not believe a back calculation is done using efficiency.

      As for your statement : “If this calculated value purports to be a surrogate number that more closely matches actual output than some measure of perceived level of exertion e.g. the Borg RPE scale, fair enough, but then say so, and prove that this is actually so.”

      This would be one of the most simplest things to record and prove right? But what does this establish regarding the actual physiological value of what is reported? You could take any black-box model and spit out a 3 digit number that “beats” RPE.

    • Zoltan

      If you google for walking and running efficiencies yo uwill get some researches where there are numbers in the range of 30-50%. I always wondered why there are such a wide range of running metabolic effciency vs cycling ME. And this time I dont mean the differences between the definition of delta, net and gross ME.

      But even for cycling ME is far from the universal 24%, just check all the researches about ME at different cadence, ME of subjects of different age etc.

    • Paul S.

      Sigh. Not this again. The claims are nonsensical and are easily disproven by observation on any sunny summer day. Efficiency is input/output, and for cycling and running and walking the output is miles (or km if you’re a supporter of French imperialism) traveled. My SUV isn’t more efficient than the hybrid I used to own because it needs to generate more energy to travel a mile. Quite the opposite. (It is, however, way more versatile.)

  96. Simon

    Could this be a new software development approach from Garmin? Almost like an alpha test to assess the market. If the IQ app is downloaded in big enouth volumes and gives accurate data, then build it into the beta firmware program, and take it from there?

    Seems like a sensible approach

  97. Alessandro

    Garmin reference’s:
    paper from 1964,1976, 1980, 1983. One from 2008 and one from 2011.
    I don’t know what kind of study performed (or used) Stryd, but I think that if Garmin used only this scientific papers, it’s a bit poor!

  98. Alexandre

    Regarding barometric watch. What are the setting of you forerunner 935 for calculating D+. I’ve tested, ‘Auto’, ‘Baro’, ‘Altimeter’, neither one is correct or giving a close value to the real D+ done durring the race !!??
    Is there a fix or a way of using it correctely ?
    Is it the same with all other brand watches?


  99. Robert FPUE (Future Power User Extrodinaire)

    Please forgive my ignorance but can power be used to structure your training? For me the most useful thing about any of these metrics is if it can be translated as a target for training. I train based on heart rate zones, I also use pace zones (wish Garmin included a plan that utilized both). Could training be focused on power zones, I mean it appears this incarnation of power for Garmin will not include training plans, but could it?

    It also be nice if some of the other metrics could become the focus of runs. I would love if my Garmin could coach me on improving areas where I seem to lack and find out if that improves my running. Currently my Ground Contact Balance seems like something I should work on.

    • Aaron

      Yup. The zone based training theory for specificity in workouts all applies to power running just like it does for HR and pace.

      The catch currently is you can’t get that info sent to the Garmin watch and use it real time – so you have to do it mentally in your head and know your target zone.

      But you can definitely do post workout analysis by zones and there are threshold test and zone recommendations just like pace and HR and software platforms let you set up FTP and power zones for running.

      You may also be able to do power training zone on other watches such as Suunto or Polar w/ Stryd? (someone please chime in here)

  100. Chris H


    Do we know if there will be 3 or 5 second power smoothing for this? I’ve had Stryd for a long while now (2+ years) and I find it almost useless. Unlike cycling with an Edge device out in front where power is clearly visable, running requires you to raise your arm to see the Power data. This is almost useless for me as the values are jumping all over the place like they do with cycling power meters without any smoothing.

    Seeing the data after the workout is done hasn’t been beneficial for me because it basically comes down to me using RPE during the workout and seeing how that correlates with the data afterward. The only solution I can think of is the headsup display in Recon or Garmin Varia Vision. Smoothing would at least make the numbers a bit more stable for the glance while running IMO

    • Brian

      Stryd offers 3sec, 10sec, lap, and average power “smoothing” factors for its data field in Garmin watches.

    • Chris H

      where is this enabled? I wasn’t able to do anything but add the Stryd Garmin IQ field which is just POWER. No smoothing options are listed nor could I find them. Excuse me if I’m just thick skulled!

    • Brian

      You choose it under settings in Garmin Connect Mobile for that particular data field.

    • Chris H

      But I want it in real-time during my workout, not after the fact in post analysis. That’s my point here….

    • David

      Garmin has stated there will be options for the CIQ display, I assume they imply you can choose instant vs. 3 second, 10 second etc. averaging.

    • Hi Chris,

      Disclaimer: I am with Stryd

      It is possible to get real time averaging using the Stryd Power data field. You can find instructions for installing and using the Stryd Power data field here: link to stryd.com

      We built Stryd PowerRace to solve the “raise your arm” problem. Set a target in the PowerRace app and you get notified via vibration if you leave your power target. You do not have to worry about checking every 10 seconds. You just have to run and PowerRace tells you when to adjust! Learn more here: link to blog.stryd.com


    • Shawn

      Thank you for this info..

    • Su-Chong Lim

      “Seeing the data after the workout is done hasn’t been beneficial for me because it basically comes down to me using RPE during the workout and seeing how that correlates with the data afterward.”

      Bingo. I think you nailed it. Smoothing out the values and giving you a number that you can conveniently see in real time (not difficult if that number were truly to be useful) could give you a number that you can use to more closely monitor your output than your own RPE. Maybe. But most people have no idea how useful the RPE (or some internal representation of it, i.e. your own fuzzy logic Exertion/Intensity scale) can be if they only were to develop that perceptional skill. Having that watch number displayed in watts is misleading, I think. We’ll see how this develops as a useful refinement of one’s own RPE (and HR). I’m sceptical at this point.

  101. Cary

    I know Ray that you mentioned this several months ago and made your position clear but as a Stryd user and marathon trail runner I can say that the most valuable part of the experience for me is pacing. In my personal experience running off of a target power as monitored by Stryd to the 935 is by far the best way for me personally to set and maintain realistic pacing over hilly terrain and long distances. Again, in my personal experience, setting a target power for a given run and maintaining this using their PowerRace CIQ widget results in much more successful training and races over long distance runs of 20+ km with 500-1000 m of climbing. Clearly there are expert runners who can constantly adjust their pacing as appropriate under these conditions but for an amateur endurance athlete I find this information invaluable even if it is not an absolute number. LOVE the site and thanks for all of the work you do.

  102. Shawn

    Fantastic article. Everything you mention related to the measurement, the compitition and motive for Garmin behind this makes total sense and is what I have wondered much about since learning about companies like Stryd…

  103. JTH

    So far I’m not convinced with Garmins power numbers. From the mountain run seems there is a lot more variance to power reading, reading higher uphill, and lower, actually much closer to Stryd downhill. Stryd had this problem also in the beginning, but they largely addressed this with recent firmware update making the device a lot more usable for pacing on varying terrain.

    What baffles me even more is that the flat run power reading is such high for Garmin. If the final release will be like that I’m not seeing myself using Garmins power data field next to Stryd. It’s a bit shame as otherwise I could use it at least as an alternative source if I left Stryd home, or if it would malfunction so I’d have to order a replacement.

    I’ve run a lot with the Stryd and I know I can trust the numbers to very good extent, even if not perfect the model they use is already very good. They also separate the form power component which can give valuable data to user. For example doing comparable interval workouts in different shoes can show in practice how form power can be lower in lighter shoe even when total power is same. This can also be seen in practice as faster laps.

    It has also been clear to me from day one that the Stryd team is constantly improving their model and listening to user input. For this kind of support and dedication I think I’ve got huge value for the money I spent on Stryd. I spent a lot more on my F5 and I just don’t see that kind of interaction happening with Garmin. Although I admit the watch has improved a lot, getting new features etc. so it’s not all bad for Garmin, but I know there are also a lot of users left without support with sensor connection issues etc.

    In the end I believe this is not the end to Stryd but just to show how far ahead they are of the competition. They are the true pioneers to running power.

  104. Jamie Sinclair

    My issue with the big differences in power readings would be when linked to training peaks and the PMC. I love the PMC, and feel that the TSS that stryd gives me compared to the the TSS via HR seem about right. If Garmin numbers higher then TSS higher, thus this will effect the form, fatigue, fitness metrics which I use to taper.

    • I’d argue though that TrainingPeaks and others (like Strava) should have zero link between running and cycling power. They shouldn’t bleed into each other from a stats standpoint.

      I think the challenge we have in general is that there’s no real proof that any given companies numbers are right outside. So while it’s handy that Stryd’s numbers tend to match our powers, it’s only handy if that matches from an accuracy standpoint. Else, down the road it’ll bite us.

  105. Nathan B

    After looking at some of the elevation charts on my Garmin Edge 520, I would suggest that they’d be best off taking GPS elevation into consideration as well. Perhaps this could be what causes the 150w difference?

    I have often wondered why these the bike computers (and foot pods) don’t have some kind of digital spirit level in them, so that they can read the gradient at specific points?

    Say you Zero offset your bike computer when you know your bike is at 0 deg, and from then, it would know your gradient based on the angle of the bike computer.

    The same could work for the point of impact in a footpod.

  106. Sam

    Ray, I was looking around the USPTO website and I came across an application from Garmin for ski power. Do you have any thoughts on this? To me, it seems like there would be too many variables (i.e. measurement from ski poles/gloves and skis/boots) and it would be ridiculously complicated (I do concede that Garmin definitely has people that are far far far smarter than I so I’m sure if anyone could do it, they could). Have we begun to become too obsessed with power and tried to find it in too many places?

    Link: link to appft.uspto.gov

    • Well that’s officially funky. As a longtime skiier/racer, I can’t even begin to wrap my head around this. That said, that’s probably because I haven’t read through it fully.

      The guys listed are from Garmin’s Cochrane office, which Garmin has slowly expanded over time to cover many advanced technologies. Much of the staff originally came from ANT+ (there’s a hard line between Garmin and ANT+ for employees, so it’s effectively living moving companies).

      One of the things that big companies are good at that you and I suck at, is putting patents out to protect future ideas. So while you and I might have a semi-functional idea, we wouldn’t bother to patent it. Whereas Garmin knows it might be worth something someday, so just plops it out there as a patent to be safe.

      Garmin has been slowly adding/focusing on skiing in recent years, but it’s really a very slow march with incremental stuff each year. In order to be taken more seriously they’d need to make Garmin Connect better equipped to handle skiing. Most notably update things like laps to ‘runs’, and then adding in winter-focused ski maps of resorts.

    • Paul S.

      Wow, that set off my BS detector.

      First, as a cross country skier, to first order, downhill skiers produce no power at all. Why? Because the forces generated by the skier are perpendicular to the direction of motion, so they do no work. The lift produces all of the energy, and the skier manages that energy on the way down by reducing the slope (swerving back and forth across the fall line, unless he’s one of those crazy downhillers) and increasing the friction of the skis with the snow when desired. None of the forces are in the direction of motion (friction doesn’t get credited to the skier; it’s not the skier’s muscles that are producing the force to overcome the frictional force), so no work, no power. (The forces a cyclist produces along the crank arm also do no work.) For downhillers this is of absolutely no use whatsoever.

      I didn’t read the entire thing either, but of course it’s basic physics that measuring the external forces on an object and the velocity are both required to compute the power. It’s nice to see that they actually recognize the importance of the poles, since in x-c they’re not outriggers but propulsion devices. So yes, measuring the forces produced by the poles and skis and measuring the velocity are required to measure the power produced by a skier, but that’s just basic physics, and I didn’t think you could patent basic physics. I hope they do actually go through with this, but I bet it’ll be hard and will probably come to nothing in the end.

    • What would be semi-interesting is actually the inverse of what we’re talking about: Which is to measure braking power. For a downhill racer – any braking force would be considered wasted energy. The challenge would be determining the difference between a heavy g-force turn that nails the line (between the gates) perfectly, versus scrubbed speed do to being over/under the line. But coming from the racing background, I’m not sure how I’d use this. I’d think that the overlaid line on a HUD would be more useful, combined with current course conditions (e.g. the ruts, snow resistance). And even then…I’m still not sure.

      But given there’s no mention of downhill skiing in that application, it does seem wholly focused on XS skiing.

      As a side note, there are folks looking into braking power meters for mountain bikes – with roughly the same thought. Measuring braking is usually wasted energy. Obviously, there’s a safety aspect to balance there.

    • Paul S.

      Maybe strain gauges in the bindings and some kind of sensors on the base of the ski that could measure transverse slippage of base and snow. From watching downhill, though, it seems that the courses get pretty rutted and the skis aren’t always on the snow, so it’d be pretty complicated. I don’t know if in the end sensors would do any better that the training/body sensations that are used now.

      I think we’re going to need new terminology, though. Right now power meters are devices that try to measure the power exerted by muscles to produce forward motion. Brakes produce power, all right, but they take (almost) no effort to do that. So we should probably call these meters something else. The whole point of brakes or choosing a line going downhill is to prevent a controlled descent from becoming an uncontrolled one, and that’s a matter of psychology/self preservation, not energetics. (The fastest way down is always going to be the fall line, but that may result in weeks in traction.) Maybe sensors would help people to learn their limits faster, otherwise, I don’t see the point.

  107. Triwolf

    Any idea if the Run Pow App will be distributed via Garmin Connect or as additional App with Firmware Updates in compatible Devices

  108. Nico

    Just wondering: could it be possible to add the barometer into the pod…
    Or in a tempe-baro pod.
    That would allow the thing to work even with the 735…
    Multisports watches (F5 or 935) are really too bulky to wear with a formal shirt…
    And 735 really lacks this barometer. External barometer would do the job :-)

  109. Rave

    I have a Fenix 3HR, because they dragged their feet on the replacement for the 920xt There is NO WAY IN GODS GREEN EARTH I am replacing my damn watch because some dev-ops people are too lazy to write code. It is obviously possible because Stryd did it. Upgrade yearly or have electronic gear that is useless? I will never recommend Garmin again. I will buy the Stryd and keep my watch. Cheaper in the the end, what choice did Garmin really give me? Now I get to find out that someone else might be better than them. All Garmin items off the Christmas list. This would be like Apple saying they no longer support the Apple 7, “sorry, different rev'” Still shaking my head

  110. Nacho

    Is there any way to test out de RunPow app? I already have connectIQ 2.4

    • No, it’s still in Garmin private beta. As I noted somewhere else in the last few days, the date has slipped a bit to Friday, December 8th.

      Randomly interesting: I’ve found much closer correlation between Garmin RunPow and RunScribe Plus, than with Stryd. Obviously, I still have no idea which one is truly correct.

    • eyez

      Garmin doesn’t listen do they customers.

      I dont know why im not able to build structure workout based on power like i do for cycling?

      WTF ?????????? with that firma garmin

  111. Simon

    Is my Garmin 630 useless if i want running power? (garmin or stryd)

  112. Wojtek

    Hi all Fenix 5 and Fenix 3 users (and maybe other affected units) Check your Garmin connect, whether your Elevation Correction is Disabled or Enabled. If it is Enabled by default, then you have a faulty unit. This fault is multiple times described in forums, but unfortunately, Garmin does not acknowledge it. It results in 4 minor faults
    1. Elevation Corrections are Enabled
    2. Software X.00 is reported as X.X.0.0 on Garmin Connect
    3. Connect IQ Apps do not record data into Garmin Connect (no running power!)
    4. Connect IQ Apps do not update.

    If you have this fault, report it to garmin immediately, as they need a lot of time to investigate it.

    @Ray, ever heard of it? It is supposedly error in Garmin Connect backend, that Garmin cannot fix, thus they in some cases exchanging the affected units. It can be fixed temporarily by changing serial number in the fit file and upload it again!

    • I haven’t personally seen that problem, nor looked for it on the Garmin Forums*, though I have no reason to doubt there’s some odd edge case.

      *I’ve spent far less time on the Garmin forums since the re-design this past summer, just generally find it a mess.

    • Dom

      I had that problem for months with my Fenix 3. Eventually it was corrected without having to replace the watch. I suspect they have a database of serial numbers for devices with barometers which don’t need elevation correction, and said database is patchy for the Fenix watches, maybe because there are just so many variants.

      There are loads of threads in the forum, going back over a year (for example this and this, and they did correct it for some units, so it’s disingenuous at best if they’re not acknowledging it.

    • Wojtek

      most frustrating it is, that the polish support seems to be really surprised by the error. I found also several threads, discussed with many users, who investigated it many times. The problem is, that it’s not just about the elevation corrections. It’s about not working connect IQ, including probably the newest running power feature, it’s about software updates that do not work automatically.
      I am really shocked, that such proven case isn’t described in Garmin internal FAQ. I am really frustrated with Garmin support, who has totally no idea of what it is about.
      Example: one of the minor issues is that 6.00 software is reported as on Garmin Connect. I described it in my email to support. And what they did? They found the on my Garmin connect and asked me, why didn’t I downgrade to 6.00 And there was never a 6.6 software release for Fenix 5.
      Anyway, why am I writing it here: because many of you are waiting for the new Garmin feature. If you have this bug, you won’t be able to use it. And don’t count on a fast solution of your case, as Garmin does investigate each case from the beginning. So check your Garmin connect and report the issue ASAP

  113. Gennaro

    I am a cyclist who occasionally runs, and I was considering having some fun with running power with my Vivoactive HR. At this point I set up to buying the RD-Pod, but I stopped just short of pushing the “buy”button because it looks that my watch won’t work with the pod.

    Could you please confirm if that’s the case? If so, I’m left with the only choice of an RD HR strap, which might not be worth it because I just never use a HR strap while running, I’m just happy with the data from the watch.


  114. Jason Gaul

    I have a 935, just wondering if there is any set dat yet for the release?

  115. Joe E

    Wonder if AppBuilder will work with Garmin data field. Works great with Stryd to give 2 power fields (i.e. I use Stryd for Lap Power and AppBuilder to get 3s Avg Power).

  116. Any update on this, gone past the 22nd now and no sign of it in the ConnectIQ store ?

  117. Ignacio Baldovino

    Could you clarify if vivoactive HR is compatible with this? it does have garmin iq, but the pod nor the hr strap with metrics appear on the campatible list

  118. Scott A Lesanko

    I have a garmin 630, if I read the article correctly the only way to get a “power” reading for my watch is either to purchase a stryde or upgrade watches?

    • yes your option is to: upgrade watch or get STRYD or get RunScribe

      This might have one or two missed off but broadly compatability is as follow (i would be interested to know if wrong):

      RunPow: fenix 5*/x/s*/935, va3, va hr,
      RunScribe: all of the above plus – fenix 3/hr, 230,235,630, 735,910,920, Va1, v800, spartan, ambit 2/3
      STRYD: ALL 2 of the above plus – 310xt and apple watch 2/3

      * Check connectivity

    • Scott

      Hello the5krunner,

      Have you tried both Stryd and runscribe, if so which would you recommend?


  119. Nathan Walker

    When is the RunPow app expected to be released? And it will be in the Connect Store when released?

  120. Alexander Momberger

    Hallo everyone! So, Tomorrow on december 8th I’ll try out the Garmin RunningPower! I just bought a Garmin Running Dynamics Pod (RD-Pod) and I have a Fenix 5. And here is my question:
    Will the fenix 5 use the accelerometer of the RD-Pod to show a better instant pace? When using GPS, the pace is smoothed by 5-second sampling. So will the RD-Pod improve the instant pace? Also: will the RD-Pods accelerometer be used to better track when GPS is list, e.g. if you run through a tunnel? If so, why doue not the fenix 5 use it’s onboard accelerometer to improve the instant pace and the Tracking, when GPS signal is weak?

    Thank you a lot for your help. This is simply by far the best resource for insight!

  121. Tim

    Dec 8th and nothing yet. At least not for the morning run. Connect IQ 2.4.1 and Software 7.0 automatically installed over night though. But can’t find the data field in the store…

  122. Dom

    Power fields are in the store now, including a combo with current, average, lap and last lap. Interestingly, it uses weather info from the phone to compensate for wind. We’ll see how well it works, but that is unique right now AFAIK.

    • Jason

      Hi guys,

      How do I get the “combo running power” data fields to show on my Garmin 935?. I chose “Custom Data” on the watch under “add new data” screen and then the 4 data field screen and then “ConnectIQ fields” and then “Combo Running Power” but it doesn’t appear to add it for some reason.

      Very confused! :)


    • Aleander Momberger

      Just replace “4-Data-Field” to “1-Data-Field” screen. The combo field is technically one single ield, however you’ll get all 4 fields displayed. I’m goind to try the new runningpower tomorrow on my fenix 5. I wonder if there will be a follow-up article/review from Ray. I really hope so, because I have very high hopes for Power-Measuring for pacing.

    • Jason

      Thanks Aleander! Worked straight away. :)

    • Within the next hour or so, just editing some photos for it.

  123. Gennaro

    December 8 arrived, the Running Power Data Field is there, but it is NOT compatible with VivoActive HR :-(

    • Indeed, more on that in a bit in a post.

      Garmin says it was a miscommunication, and looking at the e-mail strings I can see how one could see that. But at the same time, it brings up a very valid concern about how Garmin is shifting their general practices with how they administer Connect IQ, and it’s no better highlighted than this data field.

    • Gennaro

      In the end it was a good idea not to buy the RD Pod :-)

      Anyway I am very skeptical about wind power estimated from weather forecast, it seems to me as good as just guessing it.

  124. It worked flawlessly on a morning run. I did a screen with lap pace, power, and lap power. Link to tweet with a couple of screen shots from Garmin mobile app. link to twitter.com

  125. Graeme Stewart

    Going to give this a bash with my HRM-Run and fenix 5. Totally stoked that it’s a free download, and no new purchases required. Kudos, Garmin. Kudos, indeed.

  126. Andrew

    Ray, any idea why there is an inconsistency between the run power graph and the actual average power lap splits? For example, this run, you see the distinct changes in power/pace in the graph, but the lap split data shows it as pretty consistent?

    link to connect.garmin.com


  127. Jan Jansen

    I think, that in order to get a better idea of the power you’re using on running. You best take your heartrate say with a steady pace for running on about 160 bpm and compare it with a steady pace on cycling with 160 bpm. Then you will get a better feel on what the offset in cycling vs running would be. Cause you’re body is nothing more than a machine using energie to get itself moving. It needs the same levels of oxigen for the same ammount of power. Wathever it is your doing. If you use all of your body or just 3/4 to get forward or climbing or swimming or wathever…well…that’s the power you currently are using. That is the thing i miss in this overview. But as it is right now. Seems that the stryd pod is the most accurate at this moment

    • Su-Chong Lim

      A major problem with your initial concept is that you are assuming that heart rate is a reliable predictor for work performed. However, while HR and O2 consumption rate (you are correct that this is a good measure of fuel consumed) are reasonably linearly correlated for individuals performing across a range of varying intensities during a single sport such as running, biking, etc., the same individual will manifest considerably different HRs while running, biking or swimming for a given fixed O2 consumption rate.

    • Aaron

      This is wrong on so many levels and completely misses the point of training with power. Please read the literature, either the Run with Power book or the stuff Stryd has recently put out.

  128. Allan

    I know I’m in the minority here, but I was wondering if this could accurately track my distance skated when i’m playing ice hockey. It would be interesting to know how far I’m skating during a game.

  129. JT

    Interesting article on the sources of error in VO and GCT on power.

    link to georgeron.com

    Makes sense how Garmin and Stryd would supposedly measure the same thing and still be 100 Watts different!

  130. Su-Chong Lim

    I have tuned out of this discussion because I have been somewhat skeptical about the science behind how running power has been derived. I’m not sure my underlying view has changed since. But over a week ago I accidentally started barefoot running (I got off my exercise bike and got immediately onto the treadmill without putting my running shoes on). It was surprisingly OK. A few years ago I thought I had tried it and it was uncomfortable — I think it was outdoors on asphalt — so I quit. But, as I said, ihis time around it was reasonably comfortable so I continued for a k. I did a bit of research, and found there was a whole bunch of technical support and advice for barefoot runners. I have since continued barefoot running on the treadmill, and have adjusted my gait to land with bent knee and on my forefoot and allowing the calf/achilles mechanism to drop the heel to make brief contact with basically no impact at all — all standard barefoot running techniques.

    A brief skimming of the barefoot running literature suggests there may be a modest efficiency gain that is not merely the difference in energy cost saved in not having to accelerate and decelerate the mass of the now absent running shoes.

    I’m curious if there are any runners out there who have tracked running shod and then barefoot at the same speed while monitoring with running power measurement systems.

  131. Drew

    I just ordered a Stryd – I had no idea Garmin were already in the game. Do you know if the currentPower field in the object returned by Activity.getInfo() will return running power if you have the right watch and the hrm-tri strap? If so I will get on writing a field.

    Although initially wooed by the pseudo-physics blurb on Stryd’s website (and a couple of glasses of wine) I think if you reflect on this it is pretty much nonsense. It is not possible to calculate work directly from running dynamics. Most runners are pretty much steady state unless 100m sprinters where changes in kinetic energy are significant. The only external work done by the runner is going up a gradient and pushing against air resistance (plus any small component if the runners shoe slips on the running surface). In other words (and please don’t state the obv!) a runner at a constant velocity in a constant gravitational field in a vacuum on a flat non-slip surface does no external work (this is mere Newtonian mechanics) (I could simulate this with an ideal super-ball bouncing on for ever without doing any work). He of course consumes energy because of his internal resistances to movement and also because of how muscles work. Pressing on a wall does no work but muscles consume energy just to create a static force. Similarly, a rapid reciprocating movement such as waving an arm or leg (running) will, ignoring air resistance, consume energy but do no external work.

    Measuring the kinetics of an extremity could only give a very approximate estimate of power by using some multivariate statistical correlation. Even if the correlation was excellent one then needs to reflect on what is important from a cardiovascular training PoV.

    A useful analogy might be how we look at power output of a vehicle. What is important, energy consumed and gas guzzled per unit time or power at the back wheel on a rolling road?

    To train your cardiovascular system then internal power consumption is key and traditional HR methods remain the tool of choice.

    If wishing to optimise running efficiency then external work vs internal power consumption is an interesting idea and might be a useful metric/ratio. The problem is any value for external work produced by measuring the kinetics of some part of the body seems a long shot!

    • Hi Drew,

      Thanks for your post and thanks for your support of Stryd!


Stryd supports 3rd party run power developers so you can directly access the power value from your Stryd. If you were to use Garmin’s run dynamics pod, you would have to write your own run power algorithm to get a power value for your app.


It sounds like you have great interest in the field of running power. I invite you to read our white paper at link to storage.googleapis.com. Specifically, please look at page 4. We describe what Stryd measures in the diagram at the bottom of the page.


Please let us know if you have any questions here or at stryd@stryd.com. We would love to talk!


Angus & the Stryd Team

    • Drew

      Hi Angus. This is all very interesting and certainly not strait forward (literally and metaphorically!).

      Although I am still unclear as to how pod kinetics can give the same information as foot plate forces, I can for the sake of argument accept that there is a good correlation. We could call this applied power. (I could not lift the underlying explanation of this from your paper and would love to see the underlying theory).

      This (with this one indirection) provides a measure of work applied by the runner.

      I think this lies somewhere in-between the two things we are really interested in from a “running efficiency” PoV (We have to be careful to make the distinction between energy efficiency and “running efficiency”. The runner at the end of his race has no more kinetic or potential energy than at the start. He is zero percent efficient.) We are interested in the speed and the cost in metabolic power.

      Speed vs applied power is interesting and might provide feedback to help improve running form. We should not forget however that running form will affect power efficiency (applied power/metabolic power). An example would be an extremely short stride length and very high cadence where a lot of power is consumed accelerating the limb when not in contact with the ground.

      My Stryd has arrived so I am interested to give it a whirl.

      I would also like to start developing on Connect IQ. My first field would be to improve link to apps.garmin.com which attempts to find optimal cadence. I am not sure it works that well with the present work calculation based on HR.

      All the best


    • Drew

      Hi Angus.

      I love it! I suspect a graph of HR and power at steady state is at least a monotone so definitely useful. What beats HR is the speed at which it changes. When interval training with HR zones you have to anticipate the interval and pick up the pace in advance then towards the end you know you can coast down into the next phase. You have to guess the right effort at the start then adjust according to HR once it has caught up. As you fatigue this changes. If I get an inaccurate HR for any reason (optical HR in cold and wet conditions) I blow up trying to get in the zone and it ruins the whole session.

      This is so much better!

      I think it needs a steady state calibration with HR zones. I need to know my lactate threshold power. I need to investigate your software ecosystem and see what is already possible and what I need to develop on Connect IQ.

      Good job!

      All the best


  132. Scott

    Ray, while we don’t have a good way to measure the accuracy of running pods, don’t you think we can get a general idea based on what we see with our cycling power, heart rate, and perceived effort? I mean, for me, to maintain watts of 400-500 like the Garmin was telling you up that climb, my PE and heart rate would be maxed out! Which leads me to believe that Garmin is over estimating power.

    • The challenge is that as much as we want for things to align, there’s really no scientific basis for them to align. In many ways it’s kinda like HR zones. These don’t align between running and cycling and swimming. You’ll note that for most people it’s much easier to hit higher HR’s while running than cycling, and even more so than swimming. The perceived effort is skewed there.

    • Drew

      The general mechanical efficiency (GME, applied work vs metabolic energy expenditure) of muscles from experiment is not more than 25%. Stryd is consistent with this. Garmin’s estimate of power is higher and would frequently require a GME of much higher than 25%. This is not physiologically possible (aka wrong).

    • Drew,

      Except running is not cycling – we’re not looking at pure concentric work of isolated leg muscle. There is a complex concentric-eccentric pattern of movement with a fraction of energy recycled always from muscles and tendons. The apparent efficiency of running is reportedly > 40%, flip back to your papers form the 1960’s from the Milano school. Besides, from all the papers I have seen, the 25% figure of isolated muscle contraction is not set in stone. For example, some researchers report 60% ATP resynthesis efficiency and 49% ATP hydrolysis efficiency, and there itself the net efficiency equates to 30%. I would take one step before calling ‘physiological impossibility’ and put that in context with the range of values of efficiency reported in literature over the years.

    • Paul S

      But that has to be nonsense. The purpose of running and cycling is to cover distance, and cyclists do it on average faster and can cover greater absolute distances without destroying their bodies. Therefore cycling is more efficient by any reasonable definition of the word.

    • Paul S,

      Whether you cover 1 km fast/slow while running or 1 km fast/slow while cycling, power has to come from somewhere – the muscle. Contraction efficiency of muscle is debatedly 21-25% , the rest is chucked out as heat. But the devil is in the details – how do scientists study efficiency – is it isolated muscle, is it in-vivo, what’s the activity, what the muscle temperature? There are several considerations. On the other hand, the apparent efficiency of running, when taken together with the recycling of energy within the MTU of the body, is not just 25% – that is artificially low. This makes designing a powermeter to estimate ‘power’ a bit troublesome, you have to give a user ‘half the story’ and on top of that, tell him his/her efficiency maybe low when in fact that may not be the case at all. R

    • Paul S

      That’s exactly my point. I don’t believe that running is somehow magical, that it creates super athletes. The muscles are the same. Same level runners and same level cyclists are going have about the same ability to generate power. Cyclists have tendons and mitochondria, too, and I don’t believe that runners tendons are springs while cyclists are spaghetti noodles, and I don’t believe that runners have super mitochondria. So look at the outputs, and there you see that cyclists are faster than runners. The story that the researchers tell themselves that “harrumph, maybe I get passed by old men on bicycles all the time, but I’m more efficient” is just nonsense. They’re giving credit to runners for dead losses that they don’t give to cyclists. Again, the purpose of running and cycling is to cover distance. Put Tom Dumolin in a marathon on his time trial bike, and he’s going to be waiting at the finish for over an hour for the first world class runner to finish.

      As for running power, it looks like Stryd and Garmin differ significantly, with Stryd being more in line with cycling power. So if I were Garmin, I’d do what effectively the already do with their cycling power meters: calculate the number they think is the total energy expenditure of the body per unit time (which they do along the way to give a calorie number anyway), and divide by 4.

    • Clarification. There is nothing to state that the apparent whole body efficiencies in cycling and running must be equal. Within the scientific arena, the mechanical efficiency of cycling is always reported lower than that of running despite adjusting for methodology (including external and internal work rates).It is because running is different biomechanically, it is not just concentric pushing work. (It is also not about whether cyclists have noodle tendons or not.) Applying the factor of ‘4’ in your case basically translates running workrate into a cycling workrate. Now that may “approximate” actual workrate in the case where you are running up a flight of stairs or an incline but maybe methodically false for flats and downhills. For those who like a fact based value of power for running, such a method would be considered a lazy approach. Plenty of app makers have come up with such a product…but the fact that very few are using them is telling. Garmin as a million dollar company with public stock pursuing such a flimsy idea would be laughable.

    • Paul S

      Yes, but it’s not a factor of 2 the way the ludicrous “efficiency” numbers or Garmin power would have you believe. I can believe that on average runners put out a little more power. The biomechanics is different, and running has been around a long time, enough so that both biological and cultural evolution has had it’s chance. It’s certainly easier to be lazy on a bike (something I take advantage of every time I crest a climb and start the descent), but runners aren’t magic beings. In the end, it’s simple input/output. The input might be a little higher for runners on average (but I doubt for motivated athletes). The output is much slower speeds for runners under most circumstances (I’ve been passed a couple of times by runners going up substantial climbs, but never on flat roads). So whatever extra energy the runner produces is being wasted along with much of the rest, because it isn’t going into forward motion. Ray Maker doesn’t suddenly become twice as efficient when he switches from bike to feet, but that’s what the Garmin power numbers would have you believe. He does become slower. Since cycling power has been around much longer (and is easier to understand), Garmin should produce a number directly comparable to cycling power, in other words, divide by 2.

    • Whether it’s ludicrous or not would depend on how Garmin defines efficiency and what power they are reporting. As we have find, defining clearly what you are investigating and reporting is important.

      A very easy calculation is considered based on the energy cost of running which is nominally reported as 3.8 J/kg/m with added correction factors for wind, accelerated running and other outdoor scenarios. Let’s assume 4 J/kg/m for simplicity. Therefore, for a 70kg runner, that’s an energy input = 280 J/m (independant of pace). For jogging at 2 m/s speed, that equates to a metabolic rate of 560 Watts. An assumed concentric only efficiency of 25% means actual ‘concentric’ only power output = 140W. On the other hand, if the algorithm is based on an apparent whole body mechanical efficiency of 50%, power = 280W. That is a difference of 2:1 between second and first method. Since this power includes the rate of moving the arms and limbs and possibly even the resting metabolic rate, some correction will need to be done on this. Which method is Garmin following ? I really don’t know but I would take a bet to say they might be considering the power to move the arms and legs (internal power) and they also consider things like air resistance from wind data, so the answer can’t be settled easy without understand what is being calculated and how the approach differs from another manufacturer.

      Simply saying the numbers from OEM #1 are wrong because OEM#2 says so…or because it differs from the digits on your cycling powermeter … is not the approach to take.

    • Drew

      Hi Ron
      I was wrong regarding mechanical efficiency. I had no idea running was so efficient! 0.25 is not an upper bound. (I don’t see how we can get ATP more cheaply though – ref?)
      As for why there is a difference in the power estimation between Stryd and Garmin – I suppose that depends on what is being measured and how this is being modelled. Stryd does not take wind resistance into account. More importantly, Stryd does not take into account “internal work” (the energy required to simply reciprocate an extremity) which is much greater in running than cycling. Maybe the Garmin model/algorithm does (we don’t know because it is not published).
      Despite the theoretical difficulties in power measurement for running at a practical level I have found it useful. I use it in conjunction with HR measurement and zones. It is particularly useful in quickly gauging the right effort early on in an interval while waiting for HR to catch up. It also allows you to keep up the right work intensity as a training session progresses and your HR for a given level of effort slowly rises.
      I would agree that it is meaningless to compare running and cycling power – its chalk and cheese.

    • @Drew, I think it’s important to look at what is being measured/estimated as well as the subsequent calculations used

      We know what Garmin Running Power uses as inputs

      If you look at some of the metrics from the sensors for VO, GCT, pace and compare those metrics from runscribe to stryd to garmin (where possible) … You WILL get different input numbers.

      If you change gps pace to footpod pace a(s a source of pace for garmin) you get different power numbers. If you turn on or off GLONASS, guess what?….different again.

      I’d imagine if you change from hrm-run to rd-pod you will also get different numbers in the garmin-only environment. you will even get different numbers from one supported garmin watch model to another because of variations in gps accuracy.

      there’s plenty of differences there before we even consider wind (which won’t work from a weather app in many environments in any case).

      with runscribe and stryd the sensors are all in one place (RS=2).

      they’re going to perform in roughly the same kind of way repeatedly.

      as will/might garmin, if you keep all the input sources the same.
      if you upgrade your watch then your power numbers may well change. so long as you know that, it’s fine.

      I’d be interested to hear anyone’s experiences who is relying on Garmin running power for their training and the logic for their choice (other than cost). Don’t get me wrong, GRP is a great (free) way into running with power.

    • Drew

      Hi Paul
      Running and cycling on the flat are different. Cyclists on the flat only work to oppose speed dependent forces such as wind and rolling road resistance. Runners do this too to a lesser magnitude, but a much greater proportion of energy is used just moving up and down fighting gravity. This is all wasted energy. On average over a full cycle the vertical position (and derivatives) of the centre of mass (COM) remains the same so overall no work has been done. The pod only infers the component of work done by the man during ground contact. Some of this is negative work linked to eccentric muscle activity, but nonetheless costs ATP to produce (though less than for concentric work). Some to elastic recoil of elastic structures which is a freebie.

      This extra wasted work of running can be produced more efficiently and leads to a higher apparent power output.

    • Paul S.

      But wasted energy is a loss and there’s nothing “efficient” about losses. It’s like saying that the engine in my car is 100% efficient in converting gasoline into heat. Maybe so, but that’s not the primary purpose of a car engine and the real efficiency you want to measure is how well it converts gasoline into forward motion. Maybe dead losses shouldn’t count for runners any more than putting the brakes on should count for cyclists. I understand that the energy runners waste is required by the biomechanics of running, and maybe they should get some credit for that wasted energy where you wouldn’t give it to a cyclist. But certainly by any reasonable meaning of the word “efficient”, cycling is more efficient than running because the average speed is simply higher in most circumstances. If bicycles were less efficient than running, they wouldn’t have been invented in the first place. Giving a running power 2 times what the same person would obtain riding a bike is riduculous.

    • Drew

      Hi Paul.

      I can see both PoV.

      It is down to definitions and I think some understandable but slightly sloppy thinking by physiologists. They talk about eccentric muscle activity as being more efficient. As you rightly point out this ignores the fact that this is negative work as it still costs metabolic energy. Maybe it is just too painful to acknowledge this. In reality the efficiency of eccentric muscle action is greater in magnitude but negative in sign. I suspect the calculation used in running power is of the form: time integral of |m * a_(t) dot v_(t)| where a_ is acceleration vector, v_ is velocity vector, m is mass, t is time. I know it is a bit fake. Having said that, it does correlate well to V02 and so is useful. This is why you cannot compare cycling and running power calculations. Running power is not a true measurement of applied power. If we looked at external work done running along the flat it would only be fighting air resistance and running power output would be minuscule and not reflect the metabolic cost. If we attached a pod to a bouncing mass on a spring it would record power output even though it is all for free. It is chalk and cheese. Both are useful / tasty.

    • DJ

      The only way to measure representative power output is to put sensors in the hands and legs and understand joint torques and angular velocities. Unless we can go there, any other type of power meter is to running what the iBike was to cycling – an estimation meter. It will always remain a niche product and I dont think will hit the excite too many people anytime soon.

    • Drew

      P.S. m * |a_(t) dot v_(t)| as opposed to m * a_(t) dot v_(t), in other words the integral over time of the ***magnitude*** of the (dot) product of force and velocity as opposed to a signed scalar value. This is the point at which running power becomes rather artificial, though still useful.

    • Drew

      It is a way (however impractical) but would be incomplete and is not the only way of getting a reliable estimate of work. We can use Newton’s first law f = ma. We have to estimate the masses of various moving components if we are interested in internal work. Stryd infers the position of the centre of mass from its treadmill footplate pressure model and then calculates the absolute value for work done during the ground contact period. Of course this is a bit of a confection as overall there is no change in the vertical component of velocity contributing to the kinetic energy of the runner. Runners on the flat do virtually no external work just pushing air aside. The positive and negative work of their up and down periodic motion adds up to nothing, but both positive and negative work have a metabolic cost and this cost dominates running. The calculation of applied power is therefore not a true power output measurement in an engineering sense. Bike power is. Its saving grace is that it correlates in a nice linear way to V02 (below lactate threshold). At steady state it seems to correlate (in a non-linear monotone) to HR but is more responsive / not laggy. I think this is its niche. It is a surrogate measure of metabolic effort.

      The bottom line is, what are we interested in? What is the purpose of the measurement?

      If it is power output then It is easy to measure. Look at the change in height from start to end of the race and work out the change in potential energy. Calculate the wind drag from his speed profile during the run and integrate this value over time. If you start and finish in the same place the work done is going to be minuscule and not representative of the metabolic effort of running.

      If it is metabolic cost then V02 is the gold standard but difficult to measure directly (you need a lab). HR is a surrogate of V02 (though in a non-linear and laggy way and only after you have calibrated with min HR, max HR, lactate threshold etc…). Running “power” is a surrogate of V02 but in a linear way and it changes pretty much instantaneously.

      If we are interested in mechanical efficiency thats easy. Running is virtually zero percent efficient. Running efficiency has nothing to do with mechanical efficiency. It is a measure of the metabolic cost of translating and so is rooted in physiology not mechanics. Bicycles have reduced the metabolic cost of translating to virtually nil at low speeds on the flat.

    • Andrew

      I have suggested to Stryd that they could account for air resistance / wind by looking at how the modelled centre of mass moves when no foot is touching the ground. Its deviation from a freefall trajectory gives the force from air resistance. They were pretty tight lipped in response saying it is not accounted for yet. I think they may take this onboard in future firmware updates. It is the obvious think to do.

    • Zoltan

      link to ncbi.nlm.nih.gov

      link to hetgeheimvanhardlopen.nl

      link to carlocapelli.it

      So nice to see that science is so heterogenous regarding one piece of measure. :-)

    • Zoltan

      I always interprete the difference between running and cycling for me in the following way.

      Imagine cycling. Cyclist is the engine, bicycle is the tool. Both have an efficiency, let’s say the cyclist has somethnig between 20-30% (metabolic), but let it be 22%, while the bicycle has something between 95-99%, let it be 98% (mechanical)

      And now running, which is more exciting. Runner is the engine, runner is the tool. Just let’s regard some parts of the body as the engine, some parts of it as the tool. Both have efficiencies.

      First, without debating about the efficiency of the engine, let’s consider the tool. My instinct says that the tool has an efficiency much-much lower than 98%. Whether you label it as a mechanical efficiency or a mixture of metabolic-mechanical efficiency, that’s the real trick.

      Just read what I wrote above twice or thrice, and consider it twice or thrice.

      Nevertheless I tend to agree with Ron.

    • Paul S.

      Here’s where your hand waving falls apart: the engines are the same. In particular, for triathletes, the engines are exactly the same. Bearing your weight on your feet rather than your crotch doesn’t suddenly turn you into the Hulk.

  133. Mike MacKinnon

    Garmin does not list the Vivoactive 3 as run power compatible. I feel this would be my best bang for my buck watch based on what DC rainmaker. Can people confirm if running power does work with the vivoactive 3.

    • Andrew

      I think you would need a Stryd connected as a (bike) power pod. V3 does not have a baro which is needed for the power calculation.

  134. Andrew

    If anyone is interested I have created a Connect IQ field which allows you to do complex interval training with power. This provides a stop gap until Garmin updates its website to support workouts with power. You create a custom workout with a simple expression which you can enter using the configuration options for the app.

    link to apps.garmin.com

  135. Ben

    Why does Garmin list the app as not compatible with vivoactive 3?

  136. Current devices will get the functionality via CIQ, but what about future devices? Will they get the running power baked in natively? Also, will the RD-pod work with the Stryd Data Field and the Stryd pod work with the Garmin Data Field? Or will that only be the case if Stryd updates their side to use the new RD ANT+ standard?

    • Hi Hotmail,

      Great question.

      Stryd will only work with the Stryd Power data field.

      Garmin’s RD pod and other compatible devices will only work with Garmin’s data field.

      Even if a 3rd party device such as Stryd used the standard RD ANT+ profile, Garmin’s built-in restriction prevents that 3rd party device from working with their data field.


  137. Jonah Massey

    Hey, do you reckon the Garmin watches are going to be able to read running dynamic data from a TICKRX anytime soon?


    • Only if Wahoo decides to adopt/implement the ANT+ Running Dynamics standard that’s been around for a number of years in which Wahoo had previously agreed to implement a number of years ago. :-/

  138. Alex

    I’m a recent owner of a Stryd wind device.

    I also have a Garmin Fenix 5 Plus and have been using Garmin Connect for a long time.

    There is one thing that I don’t understand when you create or program a workout in Garmin Connect : you can’t use Power in running workouts while you can use Power in cycling workouts.

    Why is that? When is Garmin going to add Power as a metric in running workouts?

  139. Marc Steingrand

    so can you use the garmin power with Zwift and on a threatmil?