Exercise Training: Blood Pressure Response in Ambulatory Subject 911459
The physiologic mechanisms involved in the human's adaptation to endurance exercise training result in the endurance exercise trained individual having high maximal oxygen uptakes (V̊O2max) and being more susceptible to orthostatic intolerance. In an attempt to delineate the primary blood pressure regulatory mechanisms affected by endurance exercise training, we compared high fit (HF), average fit (AF) and low fit (LF) subjects' reflex responses emanating from the low and high pressure baroreceptor baroreflexes during lower body negative pressure (LBNP) and selective stimulation of the carotid sinus baroreceptor using neck pressure (NP) and neck suction (NS). The data from these experiments indicate a reduction in the responsiveness of the high pressure baroreceptor reflex of the endurance trained individual and an altered interaction between the high pressure and low pressure baroreceptor reflexes. These alterations are detrimental during orthostatic stress.