Running Power Comparison
Today was windy. Today was a ‘rest day’ (hah). Today was a day for running up some hills on paths and on dirt to check out how the Big 4 running power competitors compared to each other in real-world conditions. I performed a similar test a few years ago (link) but since then STRYD has introduced a new pod, RunScribe has taken a back seat in the consumer market and Polar+Coros both introduced their own versions of running power calculated solely from within the watch with no need for any additional accessories.
Today’s purpose was to test out something with the Apple Watch 6 but I couldn’t resist donning 4 other watches to break my ‘watches worn’ record (5). Here’s the kit I used for today’s test in the popular running spot that is Richmond Park, London.
- Garmin Forerunner 745 plus STRYD
- Garmin Forerunner 945 plus HRM-PRO and Garmin Running Power CIQ
- Coros Pace 2 with native power
- Polar Vantage V Titan with native power
Conditions: 20mph NW Wind, 14 Celcius, 4-6 ‘hills’ of between 50 and 200m depending on your definition of a hill. All hills were under tree cover at times, one was next to a wall (think wind), and all except one were off-road but on fairly firm ground. The hills are all fairly steep approaching the summit, I’d guess well over 10% but I don’t know exactly.
I used dcrainmaker’s dcranalyzer tool with smoothing initially set to 20 seconds and I’ve circled the ‘hills’. from a technical perspective, the Analyzer tool is the easiest way to compare developer fields. There are other ways but they are a PITA.
It looks like Polar and Garmin show similar results. I guess there is some similarity but, as this chart shows, there are differences between them too
Coros and STRYD are similar, which is surprising as Coros can’t take into account the wind. Luckily Ray’s excellent software lets me add in STRYD’s WIND POWER as separate line (it’s still included in the total as well). The chart clearly shows that STRYD and Coros can agree when there IS a STRYD wind effect (! even though Coros don’t use it in their calls…hmmm) but that they can also be very different when there is little or no wind effect (when they should be the same …hmmm).
So that was interesting but that’s about it. I don’t think it’s worth my while spending any more time comparing the different forms of running power until there is a way to determine which is correct. I think that was the same conclusion I drew 3 years ago too.
One take out could be that these are 4 random number generators but I will still stick with my random number generator of choice…STRYD…from experience I found that it is a good proxy for effort and my guess would be that it is correct. Of course, I could be wrong.
I’m not sure you can conclude anything from this data.
Notes & Further reading
- There are two running power approaches. Polar and Garmin are similar and Coros claim to follow STRYD’s model, although without a wind sensor.
- Applicability of model: https://blog.stryd.com/2018/12/19/using-appropriate-mathematical-and-physiological-analyses-shows-that-stryd-power-is-strongly-correlated-to-metabolic-rate-across-speed/
- Slower Speeds: https://blog.stryd.com/2018/03/13/powerhiking/
- Off-road surfaces: https://blog.stryd.com/2018/12/19/what-stryd-is-all-about-setting-the-fastest-known-time-up-mt-antero-14-276-feet/
- Garmin power uses GPS pace and wind strength/direction from a weather forecast
- Polar use GPS pace