Exercise Training and Habitual Physical Activity: A Randomized Controlled Trial

Abstract

Exercise training reduces adiposity and risk of cardiovascular disease. However, the combined effects of habitual free-living physical activity and aerobic training on waist circumference, weight, fitness, and blood pressure in postmenopausal women are unknown. To evaluate the effects of habitual physical activity levels during aerobic training on weight, waist circumference, fitness, and blood pressure. Secondary analysis of an RCT. Original data collected April 2001 to June 2005 and analyzed in 2012. Postmenopausal women in a supervised exercise trial. Women (n=325) were randomized to 4, 8, or 12 kcal/kg per week of aerobic training or a control group for 6 months. All outcome measures were collected at baseline and follow-up. Changes in dependent variables within each training group were evaluated across tertiles of pedometer-determined habitual physical activity outside exercise training sessions. Changes in waist circumference and weight. Reductions in waist circumference were significantly greater with higher steps/day accumulated outside exercise training compared to lower levels in the 4 (high: -4.8 cm vs low: -1.4 cm, p=0.03); 8 (high: -4.2 cm vs low: -0.4 cm, p=0.03), and 12 kcal/kg per week groups (high: -4.1 cm vs low: -0.7 cm, p=0.05). For all groups, p-trend≤0.03. A trend was observed for greater weight reduction with higher steps/day in the 4 kcal/kg per week group (p-trend=0.04) but not for the other exercise doses. No effects were observed for blood pressure or fitness measures (all p>0.05). In postmenopausal women, higher habitual physical activity while participating in aerobic training was associated with greater reductions in central adiposity, and was supportive of weight loss compared to lower levels.