The health benefits of physical activity are believed to be related more to exercise volume than to intensity. In this 24-wk study, we examined the effect of walking volume on aerobic fitness, serum lipids, and body composition in women post-menopause, a population at risk for coronary artery disease. Of 79 women randomly assigned to groups at the outset, 56 completed the study (mean age 61.3 ± 5.8). Participants walked at an intensity of 60% peak oxygen uptake (˙VO2peak) for 60 min, 3 d·wk-1 (N = 19) or 5 d·wk-1 (N = 17), or remained sedentary(N = 20). Walking 3 or 5 d·wk-1 increased˙VO2peak (ml·kg-1·min-1) by 12% and 14%, respectively (P < 0.01). There were no changes in serum lipids in response to either program. Percent body fat decreased by 1.1% and 1.3% in those walking 3 and 5 d·wk-1, respectively; both changes significantly different from the control group (P < 0.05). Walking 5 d·wk-1 did not result in more health benefits than 3 d·wk-1, possibly due to a greater compensatory decline in activities other than the walking program, or greater discrepancies between actual and reported activity and food intake. Longer-duration programs, or simultaneous changes in diet, may be necessary to alter serum lipids in nonobese, normo-lipidemic women post-menopause.
Health, Leisure and Human Performance Research Institute, Faculty of Nursing, and Faculty of Medicine, University of Manitoba; and College of Physical Education, University of Saskatchewan, CANADA
Submitted for publication January 1996.
Accepted for publication May 1996.
The authors would like to thank the women who participated in the study, as well as Linda Stoesz, who coordinated the walking programs; Lynn Crockett(Certified Fitness Appraiser, Canadian Society for Exercise Physiology), who did the anthropometric measurements; and Rennie Benedict (RD) who did the diet counseling and analyses.
This study was supported by the Canadian Fitness and Lifestyle Research Institute (project #931R014), the Manitoba Medical Service Foundation, and the Centre on Aging at the University of Manitoba.
Address for correspondence: Dr. A. E. Ready, Health, Leisure and Human Performance Research Institute, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.