Endurance exercise performance declines with age, however, there is little information on the mechanisms responsible, especially in women. The purpose of this study was to test the hypothesis that the age-related decline in endurance exercise performance in women is associated with decreases in maximal oxygen consumption (VO2max), blood lactate threshold (LT), and running economy (RE). We determined 10 km race pace, VO2max, LT, and RE in 31 highly-trained female runners aged 23-56 yrs with similar relative (i.e., age-adjusted) competitive performances. Absolute 10 km race pace declined with age (r=-0.83). Both 10 km performance (velocity) and age were strongly correlated (positively and negatively, respectively, p&LT0.05) with VO2max and with the running velocity and VO2 at LT (LTvel and LTVO2), respectively, but not with RE. When the runners were divided into age groups {Group I (23-35 yrs), Group II (37-47 yrs) and Group III (49-56 yrs)}, 10 km performance, (VO2max, LTvel, and LTVO2 were progressively lower with advancing age. Stepwise regression analyses were performed on subjects pooled from groups I and II and also from groups II and III to determine the variability in 10 km performance that was explained by VO2max and LT throughout the age range of the sample. The majority (60%) of the variability in performance for runners aged 23-47 yrs was explained by LTvel, whereas VO2max explained the majority (74%) of the variability for the runners aged 37-56 yrs. We conclude that decreases in VO2max and the running velocity at LT are the two physiological phenomena most closely associated with declines in 10 km performance with aging in highly-trained female distance runners. However, the relative contributions of these two physiological mechanisms to the declines in endurance exercise performance in this population do not appear to be uniform with advancing age.
© Copyright 1995 Journal of Applied Physiology. American Physiological Society. All rights reserved.