Blood flow and arterial vessel diameter change during graded handgrip exercise in dominant and non-dominant forearms of tennis players

The training effect on exercise-induced maximal blood flow remains unclear. The purpose of this study was to clarify the difference of exerciseinduced blood flow, blood flow velocity and vessel diameter of brachial artery in dominant and non-dominant forearms of tennis players during graded handgrip exercise. Ten female tennis players aged 20.1 ∼ 0.1 years. (mean ∼ SD) performed 30-s static handgrip exercise in the supine position with either the dominant or non-dominant hand by increasing load at 30-s intervals until exhaustion. Brachial arterial blood flow velocity (Doppler ultrasound method) did not differ between both limbs, whereas the vessel diameter (2-D method) was significantly larger in the dominant limb during diastole both at baseline (p < 0.01) and after exercise (p < 0.05), but no difference was found during systole. As a result, the blood flow was significantly higher (p < 0.05) in the dominant limb during post-exercise condition. Muscle thickness of the forearm muscles and maximal handgrip strengthwere significantly higher in the dominant limb. Thus, the effect of training on exercise-induced blood flow specific to the dominant limb was confirmed during post-exercise due to the enlarged vessel diameter during diastole of cardiac cycle. The dimensional change in the vasculature specific to the dominant side will be included in the training effects associated with the dimensional muscular changes in the dominant forearm.