DC Rainmaker

Polar Bluetooth Smart Stride Sensor (Footpod) In-Depth Review

Earlier this week Polar announced their latest product – though, it’s not a watch.  Or even anything connected to a watch.  Instead, it’s an accessory for smart phones that further illuminates Polar’s direction and protocol strategy going forward.

The Bluetooth Smart footpod is a running accessory that attaches to your running shoes and gives you speed/cadence data both indoors and out while connected to a smart phone.  Incidentally, it’s actually the very first Bluetooth Smart footpod on the market.  I’ve been poking at it for a few weeks now – and thus have a pretty good grasp on how it works.  Note that I’ll cover below how footpods work, but if you’re looking for tons of detailed information – check out this previous ‘Everything you ever wanted to know about the footpod’ post.  While that post focuses on an ANT+ variant, virtually everything is the same here.

Because I want to be transparent about my reviews – Polar sent me the Bluetooth Smart Stride Sensor to try out.  Once I’m complete here, I’ll send this back to them and then go out and buy my own (to be able to support y’all in the comments section down the road). Simple as that. Sorta like hiking in wilderness trails – leave only footprints. If you find my review useful, you can use any of the Amazon or Clever Training links from this page to help support future reviews.

Lastly, at the end of the day keep in mind I’m just like any other regular triathlete out there. I write these reviews because I’m inherently a curious person with a technology background (my day job), and thus I try and be as complete as I can. But, if I’ve missed something or if you spot something that doesn’t quite jive – just let me know and I’ll be happy to get it all sorted out. Also, because the technology world constantly changes, I try and go back and update these reviews as new features and functionality are added – or if bugs are fixed.

So – with that intro, let’s get into things.

Unboxing:

First up is getting the accessory out of the plastic clam-shell:

Once you’ve battled the plastic (tip: just cut the top straight off, there’s nothing to worry about breaking/slicing in there), you’ll be left with the three parts inside.  Ok, four if you count the manual.

Speaking of the manual, I’ll quickly walk through those four pieces.  First up is that manual, in more languages than Lindsay Lohan probationary hearings.

Then you’ve got the cradle that you tie onto your shoes:

Inside the cradle will snugly fit the actual footpod itself:

And lastly, is the battery – a CR2430 replaceable coin cell battery.  Typically these last about a year, so once they die you just go out and spend another $3 at a drug store or the like and you’re good to go again.

Because the battery is kept separate, we’ll need to install it.  Don’t worry, it’s straight forward.  You’ll flip over the footpod and see the waterproofed to 20-meters (60 feet) door.  I’d point out that if you have your footpod on at 20-meters deep – some serious shiitake has gone down.

It’s easiest to do the removal using a big flat-blade screwdriver. This particular screwdriver might have been a bit overkill, but it was the first and closest one I saw.

Then you simply plop the battery into the battery case (not into the footpod!), and then stick the battery case/lid back into the footpod and screw it up tight.

With everything on the footpod itself ready, let’s look at how it compares size-wise.

Size Comparisons:

There’s really only one area that I can think of that I’m unhappy with, and that’s the size of the footpod.  Unfortunately Polar selected to simply swap out the communications chip on their existing footpod, rather than design something competitive to the rest of the footpod world.  To understand what I mean, see below for the existing legacy Polar S3+ footpod and the new Bluetooth Smart footpod:

Now, compare that to the footpods offered by every other company for compatibility with ANT+, ANT, and other private variations (such as the Nike+ footpod):

To help put that into perspective – the Polar one is basically as big width-wise as an egg (actually, slightly longer):

Whereas all the others are basically about the size of two quarters stacked on top.

Now, functionally-wise there’s little difference here in what the products deliver – it’s simply that one is ugly and one isn’t.  I had kinda hoped Polar would take this opportunity to slim things down a bit.

Getting it ‘installed’ on your shoe:

While fairly straight-forward, one of the issues with the Polar footpod design is that you have to unlace your shoes about 60-70% to get it installed.  So you can’t easily swap it between shoes (without having a second ‘cradle’).

Nonetheless, it only takes perhaps 2-3 minutes to do this.  And, there’s even instructions:

Once everything is laced up, you’ll go ahead and slide the footpod into the cradle:

It then gets locked in via a small rubber doohickey up top:

With that, you’re (almost) ready to run!

Pairing it to your phone:

Either before or after you tie it to your shoe, you’ll need to pair it to your phone.  Today, that means any Apple iPad/iPod/iPhone with Bluetooth Smart.  So essentially any iPhone 4s or higher.

Note, it does NOT support Android.  Again, no Android.  Not entirely the fault of Polar (though they lack an app), but mostly because the Android Bluetooth Smart fitness profile situation is a mess right now with no adoption by Google and no concrete timetable beyond “a few months” (the same as it’s been since January).  To be fair, Windows Phone is no better (actually, worse, no timetable at all).

So, Apple it is.

You’ll need the free Polar Beat app, which is Polar’s iPhone app that came out last fall.  It’s actually quite good, and is probably the most visually pleasing ‘product’ Polar has ever released.   You can read my review on it here.

Once you’ve got that all set, you’ll go into Settings and then slide “Stride Sensor”.

Once you do that, it’ll trigger a Bluetooth search for the footpod (in the event you have Bluetooth turned off, it’ll honk at you).

And, if you’ve had it sitting on a desk for a bit, it’ll also have you shake the sensor to wake it up (it uses an internal accelerometer to return it from a sleeping state).

A split second later it’ll find the footpod and you can go ahead and tap ‘Pair’ to pair it to the phone.

Once paired the phone will automatically remember it for future connections.  Remember that Bluetooth Smart accessories (sensors) can only be actively paired to a single device at once.  Meaning if you have multiple phones/iPods/iPads and happen to have the Polar App on them and happened to have paired it to the footpod – be sure that the app is closed when you’re ready to run.

Otherwise, the other devices will block the connection.  Translation: It’s a one-to-one relationship once the footpod turns on.

At any rate, once it’s paired it’ll show your battery state, as well as the device ID.  Additionally, you can remove pairing if you need to.

We’ve got one more step and then we’re ready to use it.

Calibration:

One final step will be calibration.  Though, this will actually be done post-run.  You’ll need to do one run either on a known course (such as a track or treadmill– highly recommended), or some other route to calibrate the footpod.

The reason is that the footpod isn’t a GPS device, but rather an accelerometer based device that attempts to understand your stride.  By giving it a baseline ‘known distance’, the footpod can then be calibrated for future use – at any speed or distance.

I’ll dive into this more later on.  But in general, I’d suggest doing about 800m (2 loops of a track, half a mile) as a good calibration effort.  Run a ‘comfortable’ pace (such as a long-run pace).  Typically that gives me the best results.

Running Outdoors:

Once you’re ready to run, you’ll want to find a place to stash your phone.  I just use a simple running armband to tote mine along.  You’ll go ahead and open up the Polar Beat App to begin tracking.

Assuming you walked outside with your running shoes on, the stride sensor will have woken up already – so the stride sensor will then automatically show up as paired:

The stride sensor will automatically be used for any distance or pace calculations within the app.  Though, the Polar Beat app will still utilize the GPS for producing a map.

With that, we’ll tap ‘Start’ to begin running.  As we run, the unit will automatically update pace and distance based on the footpod (again, not based on the GPS within the phone):

At the completion of the run (or anytime mid-run) you’ll be able to tap the distance data field and override it.  This allows you to then manually enter in the correct distance.  This is how you’d calibrate the unit upon a track, treadmill, or known running path.  I highly recommend track or treadmill, as even running path distances might not quite be measured exact enough.

Below, you can see I used a separate running watch on a recent run to determine the distance:

Then, I went in and manually set the distance in the Polar App:

Once that’s complete, it’ll recalculate the pace for the run, and then any future runs will use the new calibration factor with the footpod.

As is normal with the Polar Beat app, you’ll still be able to view the map of the run while outdoors:

Additionally, upon completion it’ll provide you with your session summary information, distance and calories (if wearing a Bluetooth Smart heart rate strap such as the H6 or H7).  You can swipe left to view the map (seen above), or right to see additional graphs such as pace and heart rate (again, if wearing a strap).

You can click the ‘Share’ button to share the run onto either Facebook or Twitter.  Additionally, the app will automatically upload your run to your Polar Personal Trainer (PolarPersonalTrainer.com) account online, where you can dive into further analytics.  I’ll cover that in a couple sections from now.

Running Indoors:

Running indoors is much the same as running outdoors.  In fact, it’s almost identical.  The only real difference here is that you won’t get a map of your run – since you didn’t run anywhere (though you will get a dot on the map showing where you were).  Just like before, you’ll start your run once the device has paired to the footpod:

At this point, it’ll track your distance just like outdoors using the footpod distance:

If you’re noticing a discrepancy between the treadmill and the app – you’ll want to tap the distance button and re-calibrate it to the treadmill speed.  In the case below – the two are actually very close, since one is in miles and the other in kilometers (look, you try and read Chinese to change it…).  Again, .34 miles = .55 kilometers. :)

Now note that most treadmills have some inaccuracies, mostly because very few gym’s bother to correctly calibrate them on a regular basis.  In fact, you can easily validate this (as I have many times) by jumping on a treadmill and setting a specific speed (i.e. 8MPH), and then running for a short distance.  You’ll see that the Polar app with footpod will give you a specific pace and likely will hold that pace.  Then, if you jump to a different treadmill in the gym and set the exact same speed you’ll likely see slight variations in pace.  Assuming you didn’t whack your footpod along the way between the two treadmills, this is almost always a results of the treadmill itself.

The moral of the story being don’t completely fret that you see slight differences in the gym.

Once you’ve finished your run, you can go ahead and correct the distance variation between the treadmill and the app if it’s significant, and then save your run – just like when outside.  With that, let’s start poking at the data.

Uploading and viewing the data:

Once you’ve completed your workout you can go to Polar’s site and view your run in more detail (it automatically uploads from your app based on configuring your account in the settings).  Their site – PolarPersonalTrainer.com is free – and is where all supported Polar units (watches/etc…) upload data to for analysis.  As you’ll see, the site is fairly basic, and not exactly the pinnacle of graphical or user interface design – but the core fundamentals are there.

You’ll be able to open up your activity and get the summary information up top, along with a map of your run down below (you can zoom into the map and move around):

If I click on the ‘Curve’ tab, I can enable cadence metrics to be displayed on the chart.  You can then see the line all the way across.  The brief drop you see about the 8-minute marker was getting through a fence.

And then finally, within the ‘Data’ page, you’ll notice your stride length will be displayed.  This is also where you can export out the data as well, along the bottom.

I did a quick test though and the stride did did not seem to be consumed by TrainingPeaks when importing in either of the two files (only the GPX file would import correctly). So your stride data is somewhat limited.  I’d really like to see Polar both improve their website and make it semi-competitive, as well as improve the data sharing/exporting pieces.

Pairing it to a watch:

Now I made a heading here simply in an effort to stem the tide of questions for folks asking “Which watches does it work with?”.  In reality, this section is a trick-section.  See, it works with no watches today.  Not Polar’s, nor anyone else on the market.

There exists not a single unit – or even app – outside of the Polar Beat App that can connect to a Bluetooth Smart footpod.

I do think we’ll see that change, and quite rapidly in fact.  For example, the recently announced Tom-Tom Multisport watch could relatively easily introduce support for it given it has Bluetooth Smart in it.  And, both the upcoming Bia and Leikr watches could add support.

The only requirement that a watch need have is Bluetooth 4.0 connectivity (to support Bluetooth Smart), and the firmware programmed to support this Bluetooth Smart device profile.  Currently hardware-wise that’s oddly limited to the Garmin Fenix (though certainly don’t expect support of the Bluetooth Smart footpods anytime soon) and the Motorola Motoactv (also, don’t expect any update there since that team’s been disbanded).  And of course, down the line there’s watches like the Bia and Leikr that have the hardware guts, but haven’t committed to the software side.

As for Polar’s watches – they’ve committed numerous times to developing a unit (watch/bike computer) with Bluetooth Smart in it.  Given nothing was announced this spring for it, I wouldn’t expect to see any further announcements until the fall timeframe (for either running or cycling).

Summary:

As the first Bluetooth Smart footpod on the market, Polar is at the trailhead of Bluetooth Smart devices over the next few years.  They were amongst the first of the companies to release a Bluetooth Smart HR strap, and now we’re seeing them add to that with the footpod.

The unit works well within the confines of the available and compatible apps/devices today (just one), but as long as they fully followed the protocol specifications we should see greater compatibility with devices and apps in the coming months (and years).  Polar’s previous Bluetooth Smart units (their H7 and H6 heart rate straps) both have conformed nicely to the standards, and thus I have no reason this didn’t either (the devil’s in the tiny implementation details that will only surface when 3rd party apps/devices try to leverage it).

The only disappointment is really in the size of the unit – which is purely a cosmetic/fashion item, and not really a technical one.  Though, that does have the ancillary limitation that it makes it more difficult to swap between running shoes.

With that, let’s briefly look at the pros and cons:

Pros:

– First Bluetooth Smart footpod on the market
– Works just as well as any other footpod
– Conforms to official Bluetooth Smart footpod specifications (means: not limited to just Polar devices)
– Easy to use
– No problems with free Polar Beat app

Cons:

– Roughly the size of an egg, not small like others
– Only one app supports it today (this will change though)
– Not super-easy to move between running shoes
– A bit pricey at $79

As always, if you have any questions about the unit – feel free to drop them below in the comments section and I’d be happy to try and answer them.  Thanks for reading!

Found this review useful? Here’s the super easy no-pain way you can help support future reviews! Read on…

Hopefully you found this review useful. At the end of the day, I’m an athlete just like you looking for the most detail possible on a new purchase – so my review is written from the standpoint of how I used the device. The reviews generally take a lot of hours to put together, so it’s a fair bit of work (and labor of love).

Polar Bluetooth Smart Stride Sensor ($79US)

As you probably noticed by looking below, I also take time to answer all the questions posted in the comments – and there’s quite a bit of detail in there as well. Thus, if you use Clever Training (at left) to pickup the device, you’ll save 10% on your entire order, and get free shipping for US folks.  Oh – and you’ll really help support the site!  Just add coupon code DCR10BTF to the checkout page. Thanks for reading!

And as always, feel free to post comments or questions in the comments section below, I’ll be happy to try and answer them as quickly as possible. Further, you can always e-mail me at the address on the sidebar. And lastly, if you felt this review was useful – I always appreciate feedback in the comments below. Thanks! Finally, I’ve written up a ton of helpful guides around using most of the major fitness devices, which you may find useful. These guides are all listed on this page here.