This book presents original research and commentaryon the influence of the oxygen cost of breathing onwhole-body VO2 and VO2max. The measurement and interpretation of VO2max is afundamental concept in exercise physiology. Attainment of a plateau in VO2 despite increasingexercise intensity is the primary criterion forachieving VO2max and is assumed to reflect a maximumlevel of O2 consumption by the exercising muscles. Indirect calorimetry via expired gas analysis is themost common method used to measure VO2 duringexercise and provides data representing whole-bodyoxygen consumption. Whole-body data is used toestablish the existence or absence of a VO2 plateau, and the interpretation that such responses directlyreflect the metabolic activity of the exercisedmuscle mass. Interpretation of whole-body VO2 as arepresentation of exercising muscle VO2 is thereforenot accurate as established by the research presentedin this book.