This is one of those ‘YAY days’. I tried something a bit techy & convoluted and it all worked out.
What I tried to do
It was my first run for a while to check out my Achilles (mostly OK, thank you for asking). Also with RunScribe Plus now going LIVE with their “Sensor Fusion” pace algorithm, it seemed a sensible time to properly upgrade that AND to assume that the RunScribe running power data field would be as accurate as it could be for now. My Forerunner 235 was already set up for power from RunScribe Plus so …why not use that?
Then why not compare that to the Polar Vantage V’s own version of running power?
And you can guess the rest: Garmin Running Power came from the Forerunner 935 and STRYD was conveniently recorded onto the Polar Vantage M.
What I did
I was running with a friend and a bit rushed. I pressed ‘Go’ four times and hoped for the best without testing whether any of them were paired properly and working (they are usually not paired with the right device and usually don’t work)
It was an easy 50-minute run with a couple of notably increased efforts of about a minute, just so that the numbers varied from steady-state.
I then combined the numbers in SportTracks (please don’t ask how as it is complicated) and then I eventually got this
They seemed to trend broadly similarly. Kinda.
Here is a second run of a similar type. There were two stops and one tunnel. I tried to keep a steady easy pace. The Polar Vantage V power data dropped to zero in the long tunnel which is highlighted at 26:00 (I was at one point looking at the watch and holding the arm it was on still).
And here is yet another easy run. I would say it was a pretty constant effort with only mild gradients. RunScribe and STRYD reflect possibly the constant effort I felt in executing this. What has changed on this one compared to the previous two is that I fiddled with the RunScribe on-lace position and I also calibrated the RunScribe distance in the online dashboard to correct what I think was a falsely reported asymmetry. It’s still not quite right but before it was probably overestimating distance and, perhaps, also power as a result. Having said that there is still not much difference now between RS and STRYD, below.
What to conclude
This post is really a cry for help. What do you guys/girls actually want me to do with ‘user testing‘ this running power data? It clearly is not easily comparable across the 4 technologies.It probably NEVER will be. Sure I could smooth the curves further and look at comparing averages over 1km intervals with scaling factors.
But that just seems like it will be a waste of time as no one will truly believe the raw data. The recommendation will always be ‘don’t change or mix running power technologies’…at least for the foreseeable future.
I don’t have a running lab in my back garden either. Although I do have a very nice park and a running track.
Please also bear in mind that I have a life and a real job and not THAT many of you have taken up the option to be a supporter of this blog so I really, really need to do that other job 😉
I went through a similar critical look at Garmin’s Running Power when it first came out and those posts are referenced through this link if you are interested: https://the5krunner.com/tag/RunPow/
ESSENTIAL READING: STRYD Review – In Detail, Every Aspect
Price, Availability & Discount
The Polar Vantage M retails at $260/GBP250/Eur280,
The Polar Vantage V retails at $499/GBP439/Eur499
The Polar Vantage now has general availability. There do not seem to be widespread discount yet in the EU. I’ve included the deals below but you will find a better deal at New Running Gear and Power Meter City. New Running Gear (NRG), below, were also bundling in GBP50 of running freebies.
- Power Meter City (USA) with the coupon code ‘the5krunner10’
- New Running Gear in the EU/UK with the code ‘the5krunner10’
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To me, the most important thing to find out is precision of the data, so which device will give me the same result for the same work. I don’t believe raw numbers across devices will ever be comparable, just as they won’t be comparable between people. But if a device is able to give me the same number for the same work, then I can compare the numbers between and across my own workouts.
I think those expectations are fair.
that would be a relatively low bar in one sense.
Measure of work done: if you looked at time in HR zone and then used Banister TRIMP from the 1960 you would get accurate enough results from average optical HRMs.
But then if you wanted a certain power to tie into a certain FLAT running pace then you ( I ) should be able to do that. But how to prove that then extends to more real world conditions would be difficult (and would need 3rd party studies…which are somewhat lacking)
so then would you want me (or someone like me) to run with it a fair bit and then say “yeah it seems to be a good proxy for effort” … that’s what Idid with STRYD. and it, STRYD, is a good proxy for effort IMHO.
#discuss
yes on both assioma/stryd (tho i’ve not delved to look at L/R balance on a bike PM)
I can only second that. It’s just a number. Using “Watt” as it’s name is understandable from a marketing point. But it makes those numbers debatable for scientists. Although being a scientist myself I don’t see it like that because for me as a runner that raw number (when reproducible for the same effort) is just what I need.
Therefore I found that chart quite interesting. It shows me that both units deriving their data from GPS showed the same “bouncing” (e.g. around 35min) while the pod-based solutions were not attracted by that.
BTW: You might check the ConnectIQ datafield “Running Power Estimator II” which I recently tested. The same basic idea was already available for the Suunto Ambit 2 (back in those days when Suunto supported something like that 🙁 ). For me it’s just the same as what Polar is now marketing as being the first who ever did that. Just mentioning…
Based on my own experience with Stryd, I’m very skeptical that these can do more than provide an estimate of instant, grade-adjusted pace. I’ve shared the same pod with other runners (leaving the same personal stats), and I’ve found that “watts” corresponds to pace, despite significant differences in stride and technique.
IIRC STRYD have produced validations against metabolic cost.
Yes, when you look at how that ConnectIQ datafield is implemented, it’s basically just that: “grade-adjusted pace” converted to a “power” number. Quite clear because it has no other inputs than pace and the self-calculated gradient.
When I tested it, that datafield showed a quite good constant relation to my Stryd values on flat and on inclines. The factor of the relation went completely off when running downhill (it became too low)
In that situation Stryd was also telling me that my form-power got worse. E.g. I probably spent some additional energy in “braking” or whatever 🙂
A solution that only relies on GPS/barometer (IMHO that is what Polar told us they are doing) has no chance to detect that. It would take some additional hardware to make use of other metrics, too.
Or it just adds in some magic “common” constants like “most runners brake on downhills”. But that’s not very individual, isn’t it.
Stryd does not detect incline. So flat and incline give the same power reading.
M D, I was very confused by your comment and was going to ask you to cite your source. Stryd does take into account elevation changes. After reading your assertion several times and removing from the context of the above discussion about running on hills, I realize you may mean it does not detect incline on treadmills.
In that case, you tell it the incline via the app so it can compensate.
But outdoors, hill gradients are a key part of the algorithm.
I can’t see on the Android app for stryd where to enter the incline details for treadmills
I was also looking for a calibration factor that I could set on the app as I can’t do that on one of my Polar sport watches
For my part i think the graph show alot of what i need. Comparison between different technologies – I don’t really see the need, for my part i prefer to use on (Polar) and stick to it imstead of having dozens of watches, pods HRmonitors etc. I did that with Footpods early this year, after having tored on slow response on pace shifts by GPS on my M430, I been using Polar stride sensort and all worked fine. For some stupid reason I thought RunScribe Pro would be better, but it never got instant pace as I had hoped, seems all effort went into the Plus. Then I switched to milestone Pod but the calibration always seemed to drift so now I am back to poars stride sensor again, despite not having running metrics and being BIG, i still prefer that one and spent money on pods that are now sleeping in a box… I do see that It might be insteresting to dig out the RS now and then to use to see how my stride have changed, but that was not my originally intended purpose.
back o track with running power, it seems to me that all 4 tested methods is useful as long as they are not mixed. Im not sure form the graphs, but it seems Polar vantage V might have a higher sensitivity to fast fluctuations in power than the others, but it might be adjusted before the final release. Running Power is right now not a priority for me, but if its there i am sure I will test it as an alternative to HR as indicator. Most interesting for me is the New Training Load pro and Recovery Pro features since my will to workout often seems to overrule common sense (if any).
I’m trying to export data in fit files from runscribe but there is no data on the archives…
are you asking me how i got the data out or are you saying there is a bug
That is a question for Runscribe support. They are helpful.
I would love to see the chart with a comparison of pace rather than power (i.e, if the power meter in the Vantage V will give comparable pace recordings as Stryd.)
That would of course require the Vantage V to use its power meter rather than its GPS for pace..
that’s a good question
ultimately that comes back to gps accuracy in a variety of realworld conditions (I have tested lots of devices on that basis) and also on the accuracy of any given footpod at any given speed.
https://the5krunner.com/2016/11/05/test-route-for-gps-devices/