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 physi-cal fitness parameters across blood pressure (BP) categories, and ex-plored the potential role of autonomic modulation in mediating exer-cise-induced adaptations. In this quasi-experimental study, 85 partici-pants completed a structured 15-week exercise program. All partici-pants were categorized into four groups as follows: normal BP (n=21), elevated BP (n=20), stage 1 hypertension (n=22), and stage 2 hyper-tension (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 ob-served for systolic BP with pronounced reductions in the stage 1 hyper-tension and stage 2 hypertension groups, particularly in stage 2 hyper-tension. Diastolic BP and heart rate also demonstrated significant dif-ferential 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 circumferenc-es and grip strength. Importantly, the hemodynamic improvements oc-curred 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 mod-ulation may contribute to early BP improvements; however, direct auto-nomic indices were not measured.