The role of maximal oxygen uptake in exercise performance

Maximal oxygen uptake is a measure of the functional capacity of the cardiovascular system to transport oxygen to the tissues of the body. It is usually not limited by the respiratory system, except at altitude for highly trained athletes who have a closely matched cardiovascular and respiratory oxygen transport capacity. In such circumstances, the rate of diffusion may become a limiting factor. Maximal oxygen uptake establishes the limits of endurance performance; however, the ability of the muscles involved in the tasks to utilize a high fraction of VO₂max is of great importance. The specificity and intensity of exercise training may cause more appropriate peripheral adaptation for the task performed. Since VO₂max is not a good predictor of exercise performance among groups with a high VO₂max, attempts are being made to establish other physiologic measurements of aerobic capacity. Although much has been learned concerning the determinants of maximal exercise performance, many important questions remain unanswered.