Physical Activity and Body Mass: Changes in Younger versus Older Postmenopausal Women

SIMS, STACY T.1; LARSON, JOSEPH C.2; LAMONTE, MICHAEL J.3; MICHAEL, YVONNE L.4; MARTIN, LISA W.5; JOHNSON, KAREN C.6; SARTO, GLORIA E.7; STEFANICK, MARCIA L.1

Medicine & Science in Sports & Exercise:
doi: 10.1249/MSS.0b013e318227f906
Epidemiology
Abstract

Purpose: The study’s purpose was to investigate the relationship of sedentary (≤100 MET·min·wk−1), low (>100–500 MET·min·wk−1), moderate (>500–1200 MET·min·wk−1), and high (>1200 MET·min·wk−1) habitual physical activity with body weight, body mass index, and measures of fat distribution (waist-to-hip ratio) in postmenopausal women by age decades.

Methods: A prospective cohort study of 58,610 postmenopausal women age 50–79 yr weighed annually during 8 yr at one of 40 US clinical centers was analyzed to determine the relationship of high versus low habitual physical activity with changes in body weight and fat distribution by age group.

Results: Among women age 50–59 yr, there was significant weight loss in those expending >500–1200 MET·min·wk−1 (coefficient = −0.30, 95% confidence interval = −0.53 to −0.07) compared with the group expending ≤100 MET·min·wk−1. Among women age 70–79 yr, higher physical activity was associated with less weight loss (coefficient = 0.34, 95% confidence interval = 0.04–0.63). Age at baseline significantly modified the association between physical activity and total weight change, whereas baseline body mass index did not.

Conclusions: High habitual physical activity is associated with less weight gain in younger postmenopausal women and less weight loss in older postmenopausal women. These findings suggest that promoting physical activity among postmenopausal women may be important for managing body weight changes that accompany aging.

Author Information

1Stanford Prevention Research Center, Stanford University, Stanford, CA; 2Fred Hutchinson Cancer Research Center, Seattle, WA; 3Department of Social and Preventive Medicine, University at Buffalo, The State University of New York, Buffalo, NY; 4Department of Epidemiology and Biostatistics, Drexel University School of Public Health, Philadelphia, PA; 5Division of Cardiology, Department of Medicine, George Washington University, Washington, DC; 6Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN; and 7Department of Obstetrics and Gynecology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI

Address for correspondence: Stacy T. Sims, Ph.D., Stanford Prevention Research Center, Stanford University, Medical School Office Building, 251Campus Drive, Stanford, CA 94305-5411, Mail Code 5411; E-mail: stsims@stanford.edu.

Submitted for publication November 2010.

Accepted for publication June 2011.

©2012The American College of Sports Medicine