Critical power

Critical power (CP) is a theoretically derived aerobic metabolic ceiling: the highest sustainable power output (or running speed, as critical velocity) below which a finite work capacity W' can be repeatedly reconstituted, and above which W' is depleted to exhaustion. Mathematically, CP and W' are estimated from the hyperbolic relationship between exercise power and time-to-exhaustion across several all-out efforts. CP sits slightly above the maximal lactate steady state and near the respiratory compensation point, demarcating the heavy-intensity from the severe-intensity exercise domain. CP declines with age and predicts endurance performance and cardiovascular risk; training interventions that shift CP upward increase the sustainable exercise ceiling.