MAXIMAL OXYGEN-UPTAKE - CLASSICAL VERSUS CONTEMPORARY VIEWPOINTS

The traditional view of VO2max owes a great deal to the work of A. V. Hill, who conducted experiments on exercising man in Manchester, Engla nd, in the 1920's. Hill and colleagues proposed that there is an upper limit to oxygen uptake (VO2max), that there are inter-individual diff erences in this variable, and that VO2max is limited by the circulator y and/or respiratory systems. They demonstrated that oxygen uptake inc reases linearly with running speed, but in some subjects it eventually ''reaches a maximum beyond which no effort can drive it,'' a phenomen on now referred to as the VO2 plateau. In recent years, Timothy Noakes has strongly criticized Hill's concept of VO2max. He maintains that t he absence of a VO2 plateau in some subjects is proof that oxygen deli very is not a limiting factor for VO2max. This view fails to recognize that the plateau is not the principal evidence for a cardiorespirator y limitation. Noakes rejects the VO2max paradigm of A.V. Hill in its e ntirety. The alternative paradigm he proposes is that endurance perfor mance is limited by ''muscle factors.'' Noakes suggests that the best distance runners have muscle characteristics that allow them to achiev e higher running speeds, and since running speed is linearly related t o oxygen uptake, an indirect consequence of this is that they will hav e higher VO2max values. This is exactly the opposite of how the relati onship between VO2max and running speed at the end of a maximal exerci se test should be viewed. Noakes offers little evidence to support his views, and they conflict with a vast body of scientific evidence show ing that oxygen transport is a major determinant of endurance performa nce. After carefully reviewing the evidence on both sides of the issue , we conclude that the older ''classical'' VO2max paradigm of A.V. Hil l is the correct one.