Increasing Aerobic Exercise Rx Benefits Older Women
300 versus 150 minutes of moderate-vigorous workouts each week paid off after a year
FRIDAY, July 17, 2015 (HealthDay News) -- Doubling the recommended weekly exercise amount may help postmenopausal women lose significantly more body fat, according to research findings reported online July 16 in JAMA Oncology.
Christine Friedenreich, Ph.D., a scientific leader in the department of cancer epidemiology and prevention research at Alberta Health Services-CancerControl in Calgary, Canada, and colleagues recruited 384 women whose body mass index (BMI) ranged from 22 to 40 kg/m². All women were disease-free, nonsmokers and were not taking hormone replacement therapy. Half of the women were asked to exercise the recommended minimum amount of two hours and 30 minutes a week, while the other half exercised for five hours a week.
The women could take part in any aerobic activity they liked, as long as they kept their heart rate within 65 to 75 percent of their heart rate reserve for at least half of each exercise session. Most activities involved an elliptical trainer, walking, bicycling, or running. The researchers measured each woman's body fat before and after, using X-rays and computed tomography scans, to track their progress after a year's worth of exercise.
The investigators found that the women who got the minimum amount of exercise did experience improvements in weight and BMI and, on average, lost body fat. However, women who doubled their exercise regimen experienced significantly more reduction in BMI and total body fat. They also lost more subcutaneous abdominal fat, and their waist circumference and waist-to-hip ratio decreased significantly more.