The intensity of exercise that can be sustained for a long period. Monad and Scherrer in 1965 developed the application to sport of the hyperbolic relationship between power output and time shown previously in single muscle fibres. Expressing this relationship in terms of total work done and time to exhaustion allows the identification of critical power, i.e. the power output, or the intensity of exercise, that can be sustained for a long period without exhaustion. The critical power output is typically around 60 per cent of the maximal aerobic power and can be sustained for 30 minutes or more. The critical power has been determined in cycling, running, and swimming and can be used as a measure of fitness and to set training loads. It is a construct well based in theory and relates closely, but not exactly, to the physiological measures of anaerobic threshold. The important distinction is that the critical power is a measure derived theoretically and empirically from how power output varies over time, whereas the anaerobic threshold is derived theoretically and empirically from how physiological responses vary over time.
Subjects: Sport and Leisure.