Sex-dependent associations between daily physical activity and leg exercise blood pressure responses

The authors examined interindividual and sex-specific variation in systolic (SBP) and diastolic (DBP) blood pressure responses to graded leg-extension exercise in healthy older (60-78 yr) women (n = 21) and men (n = 19). Maximal oxygen uptake (VO_2max), body composition, physical activity (accelerometry), and vascular function were measured to identify predictors of exercise BP. Neither VO_2max nor activity counts were associated with the rise in SBP or DBP during exercise in men. The strongest predictors of these responses in men were age (SBP: r² =.19, p =.05) and peak exercise leg vasodilation (DBP: r² = -.21, p <.05). In women, the modest relationship observed between VO_2max and exercise BP was abolished after adjusting for central adiposity and activity counts (best predictors, cumulative r² =.53, p <.05, for both SBP and DBP). These results suggest that determinants of variation in submaximal exercise BP responses among older adults are sex specific, with daily physical activity influencing these responses in women but not men.