Inter- and Intra-Individual Differences in Energy Expenditure and Mechanical Efficiency

Abstract

Differences in oxygen consumption between individuals and also within individuals on 4 different tasks and at 2 rates of energy expenditure were examined. Criteria are proposed for indicating differences in physiological ‘ skill ’ between individuals and in some tasks such differences were found. Weight was found to be correlated with maximum oxygen intake, the factor which sets a limit to the maximum level of endurance work, and is also correlated with oxygen consumption in two of the tasks. It is considered that differences between individuals in maximum oxygen intake is more important than are differences in oxygen consumption in tasks requiring prolonged physical effort. Gross mechanical efficiencies were estimated in order to compare the mean efficiencies of this group of men when performing different tasks.