How to apply Stryd’s Critical Power to 80/20 Zones? | 80/20 Endurance

How to apply Stryd’s Critical Power to 80/20 Zones?

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
  • #10258

    So I just got my Stryd and want to make sure I can use it right away for my 80/20 power based training. Stryd allows you to set your own Critical Power by using a recent 5k time (as an alternative to their auto calculated CP, which requires at least 3 runs for a first estimate). So I used my 5k time from last Tuesday’s time trial (the one we also used for setting HR and Pace zones) and let Stryd determine my CP based on that. According to them my CP is 268w. Now, is it fair for me to use that value and put it straight into the zone calculator/TP? My understanding is, that I only need to multiply by .95 if CP was auto-calculated by Stryd. Am I missing something or does my approach and these power zones make sense?

    Here’s a screen grab of my power zones in TP. 80/20 Power Zones in my TP

    David Warden


    Unfortunately, Stryd does not yet define what “Critical Power” means. There is no industry standard on “critical power.” Could be CP30, CP20, CP60…

    For now, athletes who take 95% of the auto-calculate CP value get close to threshold pace. However, a more accurate test is still going to be 95% of an actual 20-minute TT.



    I got a Stryd for Xmas and am still learning how to ‘drive’ it 🙂

    From the FB group, their ‘definition’ of CP is that it’s CP somewhere between 30 and 70 minutes – depending on the athlete.

    Steve Palladino who seems to be the group’s go-to guy for power-based plans reckons it’s only elite athletes at the longer durations, and most Stryders at the lower end.

    As it’s that variable, I would say certainly as David suggests, 95% of an actual TT is the best plan.

    I ran a flat out 10k a few weeks ago, so at least on that occasion, my HR,Pace and Power all tied up , so I’ve based mine on the 30 min peak according to Training Peaks for that run.

    I think it’s going to be ok – but the last couple of weeks here have been cold, and frosty or snowy, so currently I’m finding that despite executing the workouts ok on power, I’m spending a lot of time in zone x / low Z3 for HR. I’m hoping that it will sort itself out when conditions improve (even though it was cold for the 10K, it wasn’t this cold and I wasn’t struggling for traction in places)


    Thanks, Martin. I appreciate your input. I will just do a 30min TT and go with the 95% of estimated CP for my zones in TP. Sounds like that has worked for you and that’s also what David advised to do. So far loving the responsiveness of power-meter running. But Stryd’s Apple Watch app is unusable at this moment. No support for audio cues… makes it completely useless for me.

    Good luck with the weather! Temperature definitely has an effect on HR, and that’s another reason why it’s better to run based on power and not on HR.

    Happy running!

Viewing 4 posts - 1 through 4 (of 4 total)
  • You must be logged in to reply to this topic.