The effects of exercise intensity on post exercise hypotension.
Ten normotensive, recreationally active participants aged 35.0 +/- 16.3 years, volunteered to participate in the study. Average baseline blood pressure (BP) was 132/75 mm Hg for systolic (SBP) and diastolic (DBP) pressure respectively. On two separate days, participants underwent testing in a randomised, repeated measures fashion such that they performed 30-min bouts of cycle ergometry at a power output which elicited 50 or 75% of VO2 Peak. Blood pressure was monitored continuously throughout the session by the Finapres method with 2-min windows recorded at rest, 5, 10, 15, 30, 45 and 60 min post exercise. SBP was similar between the two trials and became hypotensive at 5 through 15 min post exercise. The largest decrement (8 mm Hg) in SBP occurred 5 min post exercise. DBP was also unaffected by the intensity of exercise and was lower than before exercise at 5 and 15 through 45 min post exercise. Similarly, mean arterial pressure (MAP) showed significant decrements at 5 and 15 through 45 min post exercise irrespective of exercise intensity. Heart rate was greater during the 75% intensity than during the 50% intensity trial. Pre-exercise values were re-established by 45 min post exercise. VO2 remained significantly elevated above pre-exercise values in both trials until 15 min post exercise. Haematocrit increased significantly during both exercise bouts but returned to pre-exercise values by 10 min post exercise. This study indicates that cycle ergometry at 50 and 75% of VO2 Peak elicit similar reductions in post exercise BP. Therefore bouts of mild to moderate intensity exercise may be beneficial in the control of hypertension.
MacDonald
J
J
Departments of Kinesiology and Medicine, McMaster University, Hamilton, Ontario, Canada.
MacDougall
J
J
Hogben
C
C
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D003971:Diastole; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006400:Hematocrit; D006801:Humans; D007022:Hypotension / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D013599:Systole