A comparison of physiological variables in aged and young women during and following submaximal exercise

Abstract

Previously, we have examined how aging affects the physiological responses of men to endurance exercise. In the present investigation, we aimed to extend our assessment of the influence of aging on exercise-induced responses by focusing on women. Ten young (20.3 +/- 0.3 years; mean +/- SE) and 10 aged (75.5 +/- 1.2 years) women performed 30 min of cycling at 60-65% of their predetermined peak oxygen uptake. Data for respiratory exchange ratio (RER), heart rate, blood pressure, rectal temperature, and plasma metabolites were collected before exercise, at the 15th and 30th min of exercise, and at 5 and 15 min postexercise. A two-way, repeated measures ANOVA with main effects of age and time was conducted on each variable. Our findings showed that age affected exercise-induced responses of each variable quantified. Although RER, heart rate, temperature, and lactate were significantly (P < 0.05) higher among young women, blood pressure and glucose values were greater among aged women. Moreover, unlike previous results noted among men where age-related differences primarily occurred during postexercise recovery, in women the effect of aging was detected during exercise itself. The data presented here indicate that aging impacts physiological responses of women to prolonged endurance exercise even when relative intensity (% of peak oxygen uptake) is held constant. Combined with our earlier study on men, these findings suggest that gender interacts with aging to determine whether age-related differences are manifested during exercise itself, or during postexercise recovery.

Aging obviates sex‐specific physiological responses to exercise

“…In those studies it was established that among men the impact of aging is most apparent not during exercise, but rather during postexercise recovery (Deschenes et al, ). In contrast, when examining women, we found that the effects of aging on physiological responses are manifested during, rather than after exercise (Deschenes et al, ).…”

“…After receiving a full description of the project and its potential risks, all participants provided written informed consent. It should be noted that some of the aged female subjects volunteering for this investigation also participated in an earlier study conducted in our laboratory (Deschenes et al, ). All experimental procedures were approved beforehand by the appropriate Institutional Review Board.…”

“…This then, limits our understanding of sex‐specific responses to physiological stress because we have also come to the realization that aging influences physiological responses to exercise. For example, when young and aged women perform cycling exercise at the same submaximal intensity, young women were found to have higher body temperature, plasma lactate, and heart rate (HR) values than aged ones, whereas blood pressure and blood glucose recordings were greater among aged females (Deschenes et al, ). But when examining the effects of senescence on men performing the same endurance exercise protocol, it was determined that differences in physiological responses were manifested during postexercise recovery, rather than during the exercise session itself (Deschenes et al, ).…”