POSTEXERCISE HEMODYNAMICS: INTERACTIONS OF SEX, TRAINING STATUS ...

In general, postexercise hypotension is characterized by a sustained increase in systemic vascular conductance that is not completely offset by ongoing increases in cardiac output. These hemodynamic changes are present immediately after a single bout of moderate-intensity dynamic exercise in normotensive and hypertensive humans. The mechanisms underlying postexercise hypotension are currently under investigation; however, the overall hemodynamic response maybe altered with factors associated with the menstrual cycle and following exercise in a warm environment and dehydration. As well, endurance exercise-trained men may show different postexercise hemodynamics compared to the general population. The contribution of these factors to the hemodynamics following exercise is unknown. The purposes ofthe studies outlined in this dissertation are twofold: 1) to investigate the contribution of factors such as endogenous hormones, sex, and training status on postexercise hemodynamics and 2) to further understand how fluid replacement and exercise in a warm environment affects postexercise hemodynamics in a trained group of men. Specifically, these studies investigate the role of thermoregulation and fluid balance on the reduction in postexercise arterial pressure. The studies in Chapters IVandVIoutline the menstrual cycle and training status and their role in blood pressure regulation following exercise. Chapter Vinvestigatesthe contribution of heat-stress (warm environment) and oral fluid replacement on central and peripheral postexercise 2 hemodynamics in a group of endurance exercise-trained men