Age and gender interactions in physiological functional capacity: insight from swimming performance.

One experimental approach to studying the effects of aging on physiological functional capacity in humans is to analyze the peak exercise performance of highly trained athletes with increasing age. To gain insight into the relationships among age, gender, and exercise task duration with use of this model, we performed a 5-yr (1991-1995) retrospective analysis of top freestyle performance times from the US Masters Swimming Championships. Regression analysis showed that in both men and women endurance swimming performance (i.e., 1,500 m) declined linearly from peak levels at age 35-40 yr until approximately 70 yr of age, whereupon performance declined exponentially thereafter. In both genders, the variability among the top 10 winning times in each 5-yr age interval increased markedly with advancing age. Compared with the 1,500-m freestyle, performance in the 50-m freestyle (short-duration task) showed only a modest decline until ages 75 and 80 yr in women and men, respectively. The rate and magnitude of the declines in both short- and long-duration swimming performance with age were significantly (P < 0.05) greater in women than in men. In the women, the percent decline in swimming performance over a 50-yr age period from the 19- to 24-yr to the 69- to 74-yr age groups became progressively greater from the shortest distance (50 m) to the two longest distances (800 and 1,500 m), whereas in men, no differences were observed in the magnitude of performance decline with age among the five longest distance events (i.e., 100-1,500 m). The percent gender difference in performance throughout the age range studied became progressively smaller (P < 0.05) with increasing distance from 50 m (19 +/- 1%) to 1,500 m (11 +/- 1%). The findings in this cross-sectional study indicate that from peak levels at age 35-40 yr, physiological functional capacity, as assessed by swimming performance, decreases linearly until approximately 70-80 yr of age, whereupon the decline becomes exponential. Moreover, the rate of decline with advancing age appears to be associated with event duration and gender.