Adaptations to Short-Term Aerobic Training in Younger versus Older Women, Plasma Volume and Cardiac Function

grantor: University of TorontoThe purpose of this study is to elucidate responses to short term aerobic training (STAT) among women to determine: (1) hypervolemic and cardiac function responses and; (2) the influence of hormone replacement therapy (HRT). A total of 39 females participated in the STAT program; 15 younger (19-29), 12 postmenopausal women undergoing HRT, and 12 nonmedicating postmenopausal women (60-75 years). Cardiac function was assessed using exercise radionuclide ventriculography. Evans Blue dye dilution was used to determine plasma volume (PV). V¤O2max was directly measured during cycle ergometry. Training consisted of ten sessions of cycling over two weeks at 65 to 75% of HRmax. PV and V¤O2max measures were analyzed using an ANCOVA and measures of cardiovascular function were assessed using three way repeated ANOVA. All groups demonstrated similar magnitude of increase in V¤O2max (13-17%) but without significant change in supine exercise radionuclide measures. PV expansion (7%) was observed among younger females (p < 0.05). HRT conferred no differing hypervolemic or cardiac responses. This study suggests adaptations following STAT among women do not result from central adaptations.M.Sc