The oxygen transport system and maximal oxygen uptake

This chapter reviews the historical record distinguishing the major contributors to the knowledge in this area of the oxygen transport system. The ability to study the oxygen transport system in exercising humans depended on many fundamental discoveries. These began with the isolation of oxygen independently in 1774 by Joseph Priestly (1733-1804) in England and Carl Wilhelm Scheele (1742-1786) in Sweden, the latter named this fraction of the air "fireair." Lavoisier made the first attempt to measure pulmonary gas exchange at rest along with the measurements during exercise. Most of the important intellectual concepts and hypotheses in the understanding of the oxygen transport system and its limitations were proposed by A.L. Lavoisier, E. Smith, N. Zuntz, E.G. Benedict, A. Krogh, G. Liljestrand, A.V. Hill, R. Herbst, H.L. Taylor, S. Robinson, and R.O. Astrand. Subsequent discoveries have solidified these positions and provided better quantification of the important factors or links in the process. In order to reach a more fundamental understanding of the molecular and integrative aspects of the movement of oxygen from inspired air to energy-yielding mitochondria, major contributions still are to be made. Contributions may range from identifying the genes of importance for VO_2max and their activation to the very subtle and precise interplay between central nervous factors and reflexes to match and distribute the available cardiac output optimally to active muscle and other central organs at maximal exercise.