THE INFLUENCE OF GROSS BODY WEIGHT ON OXYGEN CONSUMPTION AND ON PHYSICAL WORKING CAPACITY OF MANUAL LABOURERS

Abstract

A regression line relating oxygen consumption to rate of work has been calculated on 88 men from pairs of oxygen consumption and work-rate measurements at four different levels of work. A regression line has also been calculated for maximum oxygen intake against gross body weight for 338 men. From these regression lines it is possible to estimate the proportions of their maximum oxygen intakes a light and a heavy man would use in stepping on and off a 1 ft stool at 6, 12 and 24 times per minute. The slopes of the lines are such that both men would use similar proportions of their maximum oxygen intakes at each of the three rates of stepping ; the percentages are 26 per cent, 36 per cent and 55 per cent respectively. The distribution of the gross body weights of the 338 men has been used to calculate a body weight such that 95 per cent of the men having weights above this value would have maximum oxygen intakes of 2-0 litres/min and more and therefore be capable of a moderate rate of work. A gross body weight of 132 lb is the estimate and 43 per cent of the population lie above this weight. The ‘ tolerance ’ limits about the o.xygen consumption/gross body weights regression line are relatively narrow indicating that gros3 body weight is the major determinant in oxygen consumption when men lift their body weights against gravity. The ‘ tolerance ’ limits to maximum oxygen intake against gross body weight are wido, which suggests that the proportion of body fat influences the maximum oxygen intake value ot a given body weight.