ACTIVE MUSCLE MASS AND THE AGE-RELATED DECLINE IN ??VO2max203

Abstract

The role of active muscle mass in the age-related decline in˙VO2max of master athletes is poorly defined, particularly in women(FW Booth, J Appl Physiol 67:1299-1300, 1989). This study compared limb muscle mass and treadmill ˙VO2max responses in younger (Y, 20-32 yr) and older (O, 51-72 yr) male and female endurance athletes. Lower limb muscle mass(LLmuscle), estimated using dual energy x-ray absorptiometry, was lower(P<0.05) in older groups (Y, 18.5±0.9 vs O, 15.6±0.9 kg) and in women (♀, 14.4±0.8 vs ♂, 19.7±0.7 kg). Treadmill˙VO2max responses were: Table ˙VO2max (l/min and ml/kgBW/min) was lower in both the older groups (P<0.01) and in women (P<0.05). By contrast, ˙VO2max was similar between groups when expressed relative to leg muscle mass (Age P=0.13, Gender P=0.95). These results suggest that the age-related decline in˙VO2max in older endurance athletes is partially explained by reduced leg muscle mass, particularly in women.