What is critical power in cycling and running?

Critical power (CP) is the highest power output sustainable for a theoretically unlimited duration without fatigue. In practice, CP corresponds roughly to the 30–60 minute maximal effort. The CP model: P = CP + W'/t.

How do I determine CP and W' from field tests?

Perform 3 maximal efforts of different durations (e.g. 3, 8, and 20 min) with full recovery between. Plot power vs 1/time; the slope is W' and the y-intercept is CP. Minimum 3 data points are needed for accuracy.

Critical Power (CP) Model Calculator

Calculate critical power and W' (anaerobic work capacity) using the hyperbolic power-duration model. Predict performance over any duration from 2 to 60 minutes.

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Frequently Asked Questions

What is critical power in cycling and running?

How do I determine CP and W' from field tests?