Influence of adaptation to increased muscle work on body composition in relation to caloric intake in man

Abstract

Increased muscle work, e.g. sports training, exerts a similar effect on LBM and fat as physical activity in experimental animals. The effect of physical strain and work is manifested in every period of human ontogenesis: comparison of groups of children and adolescents, adults and elderly subjects with normal and increased physical activity reveals an increased ratio of LBM at the expense of fat in subjects with increased physical activity (Fig. 35), although subjects with the same relative body weight were compared (Pařízková 1963a). The differences are greatest in adult life (3rd decade) where the difference in intensity of the muscular load is also greatest. The athletes compared (wrestling, gymnastics) were members of the representative national teams of Czechoslovakia with a regimen of physical activity which differed as much as possible from that of the compared control groups. Similar differences in body composition of trained and untrained subjects were found by other authors (Behnke et al. 1942, Behnke and Royce 1966, Behnke and Wilmore 1974, Wilmore and Haskell 1972 etc.).