[chiquetetekik]

What is your opinion about the running poder meter “Stryd”? Is it more effective to train for power than for HR?

Topic

[allan.xperia]

allan.xperia on November 10, 2018 at 1:04 pm #14384

Even if you train for HR, the Stryd will often make it easier. I use one, and when running up and down slopes, it is much easier to keep within my heart rate targets when I keep an eye on power.

I think Scott Johnston has written somewhere in this forum that the Stryd shows wrong power when you walk very slowly up steep slopes. I can add that it also shows wrong power when walking very fast. When the walking pace is faster than approx. 7:30 minutes/km (12 minutes/mile), it seems to pass a threshold where the power will suddenly increase. And when the walking pace gets even faster, it passes another threshold where the power will suddenly decrease. This can be a little annoying if one uses fast walking for aerobic training.

[Anonymous]

Anonymous on November 11, 2018 at 8:45 pm #14396

All these running power meters use accelerometers that are calibrated to correlate the deceleration upon foot strike to running pace. That can be fairly accurate when each foot strike is the same such as when running on the the flats. Running on rough trails, uphill and down hill pretty much means the algorithms used to give power will not work. The new Polar power meter claims to correct for ups and downs by including a barometric altimeter.
My experience with the Styd (3 years ago) left me unimpressed for mountain athlete use. When going uphill and working hard (but with low impact force, it had lower power readings then an easy running pace on the flats.

From my, admittedly limited experience I would say that HR is still a better proxy for training load for our variable training conditions.

Scott

[allan.xperia]

allan.xperia on November 12, 2018 at 3:21 am #14402

The Stryd also uses a barometric altimeter for calculating the additional power for going uphill, and in my limited experience it does it pretty well. I can keep my heart rate rather constant uphill by keeping power constant.

The problem is more with going steep downhill where the Stryd assumes that you use less power because of going downhill. Stryd has admitted that their model is wrong here because it doesn’t adequately model the power that is used for doing “brake work” downhill.

[briguy]

briguy on June 13, 2019 at 2:38 pm #23524

They have worked fairly dilgently on updating the Stryd algorithms to account for “power hiking” or walking steep inclines. I’ve been using a Stryd for over 2 years and find it now does a pretty good job of correlating effort when inclines necessitate a walk in order to stay in zone.

On relatively smooth (i.e. non technical) trails it can almost always predict an HR spike before it happens. This is especially evident post-run in reviewing the graphs.

Where it still has difficulty on climbs is when the trail is so technical that it resembles stairs or step ups, it completely drops the ball in these situations.

I find that it’s still a useful tool however I have to take into account HR and perceived-effort in addition to the watts it’s measuring/displaying, especially when racing.

[Anonymous]

Anonymous on June 13, 2019 at 4:36 pm #23527

It’s great to see that Stryd is making real efforts to address the failings of their power meter for mountain running.

Scott