Changes in maximal aerobic capacity with age in endurance-trained women: 7-yr follow-up

On the basis of cross-sectional data, we previously reported that the absolute, but not the relative (%), rate of decline in maximal oxygen consumption ((V)over dotO(2) (max)) with age is greater in endurance-trained compared with healthy sedentary women. We tested this hypothesis by using a longitudinal approach. Eight sedentary (63+/-2 yr at follow-up) and 16 endurance-trained (57+/-2) women were reevaluated after a mean follow-up period of 7 yr. At baseline, (V)over dotO(2 max) was similar to70% higher in endurance-trained women (48.1+/-1.7 vs. 28.1+/-0.8 ml.kg(-1).min(-1).yr(-1)). At follow-up, body mass, fat-free mass, maximal respiratory exchange ratio, and maximal rating of perceived exertion were not different from baseline in either group. The absolute rate of decline in (V)over dotO(2) (max) was twice as great (P<0.01) in the endurance-trained (-0.84±0.15 ml.k(-1).min(-1).yr(-1)) vs. sedentary (-0.40±0.12 ml.kg(-1).min(-1).yr(-1)) group, but the relative rates of decline were not different (-1.8±0.3 vs. -1.5±0.4% per year). Differences in rates of decline in (V)over dotO(2) (max) were not related to changes in body mass or maximal heart rate. However, among endurance-trained women, the relative rate of decline in (V)over dotO(2) (max) was positively related to reductions in training volume (r=0.63). Consistent with this, the age-related reduction in (V)over dotO(2) (max) in a subgroup of endurance-trained women who maintained or increased training volume was not different from that of sedentary women. These longitudinal data indicate that the greater decrease in maximal aerobic capacity with advancing age observed in middle-aged and older endurance-trained women in general compared with their sedentary peers is due to declines in habitual exercise in some endurance-trained women. Endurance-trained women who maintain or increase training volume demonstrated age-associated declines in maximal aerobic capacity not different from healthy sedentary women.