Abstract

The measurement of the maximum oxygen consumption (VO₂max) is probably the most widely used test in the applied sports sciences. Yet this test includes three features that are foreign to the manner in which humans usually exercise. First, the tested subject does not know the expected duration of the exercise bout when it begins. Second the intensity of the imposed exercise increases progressively, sometimes rapidly from low to “maximal” work rates. Third the imposed work rate is predetermined and immutable, beyond the control of the experimental subject’s brain. As a result the tested subject’s brain merely responds to changes in work rate imposed by the experimenter and is therefore the controlled variable in the experiment. In contrast when subjects are informed beforehand of either the expected exercise duration or the distance to be covered, they will choose to run at different paces depending on the known exercise duration. The brain achieves this by recruiting the exactly appropriate number of motor units in the exercising muscles. The goal of this strategy is to complete the activity without homeostatic failure whilst still allowing an increase in pace near the end of exercise, the “endspurt”. Since the tested subject’s brain is the controlled variable during the VO₂max test merely responding passively to the externally-directed changes in work rate, so it has been assumed that the brain plays no part in “limiting” maximal exercise performance. This has in turn developed a “brainless” model of human exercise performance in which the “limiting” factors are described almost exclusively in terms of cardiovascular function. But the outstanding feature of effective human exercise performance is the adoption of the optimum pacing strategy that will avoid, not cause, homeostatic failure and profound skeletal muscle failure. Since the VO₂max test does not evaluate the athlete’s ability to choose and sustain the optimum pace during exercise of different durations, it cannot be the optimum test either to evaluate a subject’s athletic potential or to understand the biological basis of superior athletic performance.