Training-induced adaptations in the central command and peripheral reflex components of the presser response to isometric exercise of the human triceps surae

1. The effect of calf raise training of the dominant limb on the presser response to isometric exercise of the triceps surae was examined in the trained dominant limb and the contralateral untrained limb. Blood pressure and heart rate responses to electrically evoked and voluntary exercise at 30% maximum voluntary contraction (MVC), followed by post-exercise circulatory occlusion (PECO), were compared before and after a 6 week training period. 2. In the trained limb the diastolic blood pressure rise seen during electrically evoked exercise was reduced by 27% after training. However, the response during PECO was not significantly affected. 3. During voluntary exercise of the trained limb, diastolic blood pressure rise was reduced by 28%, and heart rate rise was significantly attenuated after training. During PECO no significant effects of training were observed. 4. Voluntary exercise of the untrained limb resulted in a 24% reduction in diastolic blood pressure rise after the training period, and a significant attenuation of the heart rate increase during exercise. Responses to electrically evoked exercise and PECO of the untrained limb remained unaltered after training. 5. Attenuation of blood pressure and heart rate responses, in the contralateral untrained limb, during voluntary but not electrically evoked exercise, indicates a training-induced alteration in central command.