A randomized controlled trial of continuous activity, short bouts, and a 10,000 step guideline in inactive adults

• Published in: Preventive medicine Vol. 52; no. 2; pp. 120 - 125
• Main Authors: Samuels, Tiana Y, Raedeke, Thomas D, Mahar, Matthew T, Karvinen, Kristina H, DuBose, Katrina D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2011
• Subjects: Accelerometers; Adult; Age Factors; Aged; Analysis of Variance; Anthropometry; Body Mass Index; Exercise - physiology; Female; Guidelines as Topic; Health behaviour; Health promotion; Health Promotion - methods; Humans; Inactive; Internal Medicine; Male; Middle Aged; Motivation; Motor Activity - physiology; Pedometers; Physical activity; Physical activity bouts; Physical Activity Recommendations; Randomized controlled trials; Reference Values; Sedentary Lifestyle; Self Efficacy; Selfefficacy; Sex Factors; Southeastern United States; Time Factors; Walking - physiology; Southeastern United States; Accelerometers; Physical activity bouts; Self-Efficacy; Physical activity; Motivation; Physical Activity Recommendations; Pedometers
• ISSN: 0091-7435; 1096-0260
• DOI: 10.1016/j.ypmed.2010.12.001

Abstract Objective Although several studies have examined the effect of accumulated bouts on health outcomes, the impact of recommending short bouts on activity-related behavior in health promotion efforts has received minimal investigation. Method During this 5-week study in 2007–2008, 43 university employees (8 male, 35 female) in the Southeastern United States were randomly assigned to a group recommended to achieve (a) 10,000 steps (10 K), (b) 30-minutes (30 min) of continuous physical activity, or (c) 30-minutes of activity in bouts of at least 10 minutes (bouts). Results and conclusions Repeated measures ANOVA revealed that the 10 K group showed the largest increase in step counts whereas the bouts group showed the smallest change over the intervention period, p = 0.01. Condition differences were most pronounced on days in which participants met their activity recommendation. Accelerometer results revealed that the 10 K ( d = 1.1) and 30 min groups ( d = 0.89) showed large increases in minutes of moderate to vigorous activity (MVPA), whereas the bouts group showed minimal change ( d = 0.11). Although activity recommendations did not differentially affect self-efficacy, participants from all conditions showed decreased self-efficacy across the intervention ( p = 0.02), highlighting the need to develop strategies to increase self-efficacy in activity promotion efforts.