Differential hemodynamic adaptations to identical body conditioning program across blood pressure categories: a quasi-experimental study

This study examined whether identical body conditioning program would differentially affect hemodynamic, body composition, and physical fitness parameters across blood pressure (BP) categories, and explored the potential role of autonomic modulation in mediating exercise-induced adaptations. In this quasi-experimental study, 85 participants completed a structured 15-week exercise program. All participants were categorized into four groups as follows: normal BP (n=21), elevated BP (n=20), stage 1 hypertension (n=22), and stage 2 hypertension (n=22). Because muscle mass and basal metabolic rate (BMR) differed among the groups at baseline, a repeated-measures analysis of covariance was conducted using these variables as covariates to assess the effects of time and group. Significant interactions were observed for systolic BP with pronounced reductions in the stage 1 hypertension and stage 2 hypertension groups, particularly in stage 2 hypertension. Diastolic BP and heart rate also demonstrated significant differential responses across groups. Cardiorespiratory fitness showed group-dependent responses, with significant group and time × group effects observed for maximal oxygen uptake. In contrast, no significant interactions were found for body weight, fat mass, body circumferences and grip strength. Importantly, the hemodynamic improvements occurred independently of changes in body composition and were robust after adjustment for baseline muscle mass and BMR. These findings are consistent with the possibility that exercise-induced autonomic modulation may contribute to early BP improvements; however, direct autonomic indices were not measured.