Purpose: The objective of this study is to compare the effects of fractionized aerobic exercise (three 10-min exercise sessions) and continuous exercise (one 30-min exercise session) on 24-h ambulatory blood pressure (ABP).
Methods: Eleven healthy prehypertensive subjects (28.3 ± 8.0 (SD) yr) completed three randomly assigned conditions: 1) three 10-min sessions of aerobic exercise (3 × 10 min), 2) one continuous 30-min session of aerobic exercise (1 × 30 min), and 3) a nonexercise control trial (control). The mode of exercise was walking on a motor-driven treadmill at 75%–79% of maximum heart rate (HRmax) (60%–65% V˙O2peak). Twenty-four-hour ABP was monitored with an automated ABP device (Oscar 2™; SunTech Medical, Morrisville, NC). Linear mixed models were used to compare 24-h ABP responses between trials.
Results: The mean ± SD 24-h systolic blood pressure (SBP) was significantly lower during the 3 × 10-min trial (127 ± 15 mm Hg) compared with control (130 ± 15 mm Hg) (P < 0.001). Although both 3 × 10-min and 1 × 30-min trials reduced SBP compared with control during daytime/evening (1300–2300 h), only the 3 × 10-min trial reduced SBP during nighttime (2300–0800 h, 118 ± 16 vs 122 ± 14 mm Hg, P = 0.024) and the following morning (0800–1200 h, 127 ± 15 vs 131 ± 15 mm Hg, P = 0.016). For 24 h, 26.7% of SBP values during 3 × 10 min were normal (i.e., <120 mm Hg) compared with 18.3% for 1 × 30 min and 19.4% for control (P < 0.001).
Conclusions: In prehypertensive individuals, fractionized exercise (e.g., three 10-min aerobic exercise sessions spread and effective exercise alternative to continuous exercise for cardiovascular risk reduction in this population.
School of Nutrition and Health Promotion, Healthy Lifestyles Research Center, Arizona State University, Phoenix, AZ
Address for correspondence: Glenn Gaesser, Ph.D., School of Nutrition and Health Promotion, Arizona State University, 500 N 3rd Street, Phoenix, AZ, 85004-0698; E-mail: email@example.com.
Submitted for publication February 2012.
Accepted for publication June 2012.