Maximal Oxygen Intake and Its Relation to Body Composition, With Special Reference to Chronic Physical Activity and Obesity

Abstract

The maximal oxygen intake (Max Vo2) was determined in 46 healthy male students and 13 soldiers along with the weight of body fat as estimated by immersion densitometry. In 41 the active tissue and cell mass were estimated from measurements of blood volume, thiocyanate space and antipyrine space. The correlation coefficients between Max Vo2 and a) fat-free body weight, b) active tissue, c) body weight and d) cell mass were found to be 0.85, 0.91, 0.63 and 0.45, respectively. Max Vo2 was related to blood volume and red cell volume by correlation coefficients of 0.78 and 0.69 which was shown to be dependent on relationship between fat-free weight and blood volume (r = 0.76). It was shown that students who participated in athletics had a significantly larger Max Vo2 per kilogram of fat-free body weight than the sedentary group. The largest values occurred in cross-country runners. The sedentary students who did not take part in athletics were divided into three groups according to their body composition, i.e. more than 25% fat, 10–25% fat and less than 10% fat. It was shown that there was no difference in Max Vo2 per kilogram of fat-free weight in the three groups. It is concluded that when Vo2 is used to examine the capacity to perform exhausting work the values should be expressed as Vo2 per kilogram of body weight; that when the test is used to examine the performance of the respiratory-cardiovascular system, the values should be expressed as Vo2 per kilogram of fat-free weight. It is also concluded that physical conditioning affects the maximum Vo2 independently of the mass of active tissue and that obesity per se has no effect on the maximal performance of the respiratory-cardiovascular system in young men. Submitted on December 28, 1956