Central and peripheral modulation of exercise pressor reflex sensitivity after nonfatiguing work.

Autonomic blood pressure control is fundamentally altered during a single bout of exercise, as evidenced by the downward resetting of the baroreflex following exercise (postexercise hypotension). However, it is unclear if an acute bout of exercise is also associated with a change in the sensitivity of the exercise pressor response to a controlled stimulus, such as a static contraction. This study tested the hypothesis that the blood pressure response to a controlled static contraction would be attenuated after unilateral cycling of the contralateral (opposite) leg, but preserved after cycling of the ipsilateral (same) leg. To test this, the blood pressure response to 90 s of isometric plantar flexion [50% maximal voluntary contraction (MVC)] was compared before and after 20 min of contralateral and ipsilateral single-leg cycling at 20% peak oxygen consumption and rest (control) in 10 healthy subjects (three males and seven females). The mean arterial pressure response was significantly attenuated after contralateral single-leg cycling (+9.8 ± 7.5% ∆mmHg vs. +6.7 ± 6.6% ∆mmHg pre and postexercise, respectively,