In pre-hypertensive men, evening exercise decreased night time blood pressure and cardiac work. - GreenMedInfo Summary

BACKGROUND: Clinic post-exercise hypotension (PEH) is different after aerobic exercise performed in the morning and in the evening. Thus, ambulatory PEH should also differ after exercises conducted at different times of day. However, because of the circadian pattern of BP, ambulatory PEH should be assessed considering a control condition. Thus, this study was designed to verify the effects of morning and evening exercises on post-exercise ambulatory BP averages and circadian parameters by comparing responses obtained at each time of day after an exercise and a control session.

METHODS: Thirteen pre-hypertensive men underwent four sessions (randomized order): two in the morning (9 a.m.) and two in the evening (6:30 p.m.). At each time of day, a control (C) and an exercise (E - cycle ergometer 45 min, 50% VO2peak) sessions were performed. After the sessions, an ambulatory BP and heart rate (HR) monitoring was started for 24h. Paired T-test or Wilcoxon signed rank test were used to compare the E and the C sessions at each time of day.

RESULTS: In the morning, 24h, daytime and nighttime HR were higher after the E than the C session. In the evening, nighttime systolic BP (116±11 vs. 120±10 mmHg, P=0.04) and rate pressure product (7981±1294 vs. 8583±1523 mmHg.bpm, P=0.04), as well as MESOR (128±11 vs. 130±10 mmHg, P=0.03) were lower in the E than the C session.

CONCLUSIONS: In pre-hypertensive men, morning exercise increased ambulatory HR, while evening exercise decreased nighttime BP and cardiac work, reducing the MESOR of systolic BP.