Jenkins, D. G., & Quigley, B. M (1992). Endurance training enhances critical power. Medicine and Science in Exercise and Sports, 24, 1283-1289.

Critical power (CP) is represented by the coefficient of linear regression of maximum work on maximum time. CP is related to ventilatory threshold and a fatigue threshold. This investigation determined whether; (a) CP assess the ability to perform continuous aerobic exercise and (b) training induced changes in aerobic endurance are reflected only by changes in slope of the CP function.

Untrained males (N = 12) performed eight weeks of cycle ergometer training (30-40 min/d; 3 times/wk). Six control Ss refrained from exercise for the same period. Three cycle ergometer tests were performed pre- and post-training to determine CP.

CP was found to be related to improvements in aerobic endurance ability and response to training while avoiding the problems of ANThreshold measurement and criteria based on fixed blood lactate concentrations.

The following results were reported.

  1. Work (limit) to Time (limit) r = .99 (excellent linearity).
  2. CP to VO2max before r = .61; after r = .77.
  3. Increase in CP was not significantly related to increase in VO2max (CP increased by 30%; VO2max by 8%).

Since slope changed, submaximal performance was not altered but maximal was.

Implication. A clear piece of evidence that shows performance parameters are associated with training effects to a much greater degree than are physiological measures. The best index of a training is response is the speed, magnitude, or accuracy of performance, not some isolated partly related physiological measure.

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