I’ve noticed a limitation with the way Athletica calculates training zones from Critical Power.
My CP is set at 240 W. This gives:
Z2 (endurance): around 200 W (feels correct)
Z4 (threshold): ~230–250 W (also correct)
Z5 (VO2max): 267–295 W
The problem is that my tested 5-min power is around 300 W, and I can repeat 3-min efforts at 310–320 W (around 178 - 181bpm . So the VO2max zone calculated from CP feels too low to be effective.
With Athletica we cannot manually adjust zones, since they are tied to CP. That means either:
Keep CP accurate (240 W) : Z2/Z4 are fine but Z5 is underestimated
-or artificially raise CP (e.g. 250–255 W) : Z5 is more realistic, but endurance zones become too high.
How are others dealing with this? Do you just ride above Athletica’s VO2 targets, or do you adjust CP to “fix” the high zones at the expense of the low ones?
Hey @JBB
Great question—this is a common challenge with using a single anchor (like CP) to define all your zones. You’re absolutely right: when your 5-min or 3-min power is relatively high compared to your threshold, the calculated VO₂max zone can feel too soft. Here’s how I recommend approaching it in Athletica:
Anchor your endurance (Z2) by feel and heart rate.
If your steady rides keep your HR below your upper Z2 limit you’re in the right place. That’s the anchor we care about most for aerobic development and long-term consistency.
VO₂max work? Go hard. Pacing matters more than the exact watts.
For VO₂max intervals—like your 3-min efforts—you can ride above the prescribed power if you’re feeling good and can hold that effort consistently across the set. The target range is a guide, not a limiter. Think: “Hard, but not blowing up.”
Want to level up your upper zones?
I’ve found that adding short-sharp sessions like 30/30s (e.g. 6x(30” hard / 30” easy)) once a week for a block helps improve your top-end power. Then you can return to longer HIIT sessions with better capacity and more confidence to push harder. BTW: I lead our indoor cycling sessions on Velocity (you can join us for $5usd per month) every thursday so you can truly knock it out of the park!
Keep CP realistic—it helps maintain accuracy in your aerobic zones and workout prescription. Trust your body and adjust how you ride the intensity sessions as needed. The AI will catch on over time with new data points.
Let us know how your next VO₂max session feels with this mindset—you’re clearly on the right track.
Thank you for your answer ! Very Interesting.
I’ll adapt my high intensity zones according to your advices.
These weeks were a test, at the end of my season and I think I understand more clearly the way Ahtletica works.
I appreciate a lot the possibility of asking questions in this forum, and your answers.
I’ll be back in early october for the beginning of the new season training, with a subscription plan ! See you then.
