Blood pressure reduction following accumulated physical activity in prehypertensive

CONTEXT: Accumulated moderate physical activity (PA) for 30 min in a day is the only recommended treatment of prehypertension. OBJECTIVE: We investigated autonomic modulation as a possible mechanism for the decrease in blood pressure (BP) during the rest periods in each 10 min session of PA. DESIGN, SETTING, AND PARTICIPANTS: We conducted a single-blind randomized multi-arm control trial on 40 prehypertensive (pre-HT) young male adults. METHODS: Participants were randomly divided by using random number table into four groups. Control (no intervention); Group 1 (walking at 50% of predicted VO(2) peak); Group 2 (walking at 60% of predicted VO(2) peak); Group 3 (walking at 70% of predicted VO(2) peak). BP, heart rate variability (HRV), and heart rate recovery 1 min (HRR 1 min) were measured at baseline and during the rest period after each session of 10 min over 30 min of accumulated physical activity (PAcumm). RESULTS: Significant diastolic BP (DBP) reduction (P < 0.001) was observed during the rest period after each session of PAcumm in intervention groups. An average reduction in DBP was more in pre-HT undertaking PAcumm at 70% of predicted VO(2) Peak. Decrease in the mean value of low-frequency (LF) and LF/high-frequency ratio was observed following PAcumm in all intervention groups irrespective of the intensity of PA. No significant association of reduction of BP with HRV and HRR 1 s was observed. CONCLUSION: Reduction in BP was observed during the rest period after each 10 min session of PAcumm irrespective of the intensity of PA. Autonomic modulation does not seem to be the possible mechanism for the reduction in BP during the sessions.