title: Effects of fractionized and continuous exercise on 24-h ambulatory blood pressure.
abstract: OBJECTIVE
  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.
authors: School of Nutrition and Health Promotion, Healthy Lifestyles Research Center, Arizona State University, Phoenix, AZ 85004-0698, USA.
authors: Dharini M
authors: DM
authors: Bhammar
authors: Siddhartha S
authors: SS
authors: Angadi
authors: Glenn A
authors: GA
authors: Gaesser
mesh_terms: D000328:Adult; D001130:Arizona; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000295:instrumentation; D002318:Cardiovascular Diseases / Q000517:prevention & control; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D057774:Post-Exercise Hypotension / Q000175:diagnosis; D013997:Time Factors; D055815:Young Adult