Exploring physiological factors underlying individual differences in exercise-induced blood pressure responses.

Even among healthy individuals, arterial blood pressure (ABP) responses to exercise vary widely. However, the mechanisms underlying this individual variability remain unclear. To investigate these mechanisms, 29 participants performed isometric handgrip exercise at 30% of their maximum voluntary contraction, followed by postexercise muscle ischaemia to assess metaboreflex activity. The systolic blood pressure response to exercise was not significantly correlated with arterial stiffness (carotid-femoral pulse wave velocity, p = 0.999, β = 0.000), peak oxygen uptake (p = 0.224, β = 0.168) or muscle oxidative capacity (p = 0.829, β = -0.049). In contrast, individual variability in systolic blood pressure was significantly associated with variability in heart rate during exercise (p = 0.013, β = 0.360) and the change in mean arterial pressure during postexercise muscle ischaemia (p = 0.014, β = 0.692). These findings suggest that peripheral characteristics are not primary determinants of individual differences in ABP responses to exercise in healthy young adults. Instead, variability in ABP responses might be more strongly influenced by individual differences in autonomic function. This pattern contrasts with the mechanisms underlying exaggerated ABP responses commonly observed in older adults and individuals with hypertension.