Jan. 14 2003 -- Regular exercise may not only help older women reduce their risk of disease, but it could be even more effective than dieting for winning the battle of the bulge. A new study shows moderate exercise, like brisk walking, can help postmenopausal women lose weight, reduce body fat, and prevent the pounds from coming back.
Researchers found previously sedentary postmenopausal women who began exercising regularly lost more than 4% of their total body fat and significantly improved their cardiovascular fitness levels after 12 months while eating the same amount of calories .
The active women also lost nearly 7% of their intra-abdominal, or inner stomach, fat. Excessive amounts of body fat in this area is associated with a variety of health risks, such as insulin resistance, type 2 diabetes, high blood pressure, high cholesterol levels, and heart disease.
In the study, 173 sedentary, overweight menopausal women between the ages of 50 and 75 were randomly assigned to either a moderate-intensity exercise program or a stretching program that acted as a control group. Throughout the year-long study, researchers measured changes in body weight, total body fat, and abdominal fat.
Women in the exercise group participated in moderate exercise, such as brisk walking or riding a stationary bike for an average total of about 171 minutes a week. Researchers say this level of exercise prescribed by the study is similar to national recommendations that call for about 30 minutes of moderate-intensity activity on most days of the week.
After 12 months, researchers found that weight loss among the exercisers was modest, but the loss of intra-abdominal fat was considerable and increased with the amount of exercise. Women who exercised for more than 195 minutes a week lost almost 7% of intra-abdominal fat compared to a loss of about 4% among those who exercised between 136 to 195 minutes per week.
Women in the highly active group also experienced more dramatic overall weight loss, losing an average of more than 4% of total body fat compared with losses of more than 2% among the intermediate exercisers.
In comparison, women in the stretching group had much less significant losses and even gains in these areas.
Aside from the weight- and fat-loss benefits, the study found that 84% of the exercisers also improved their cardiovascular fitness levels, which can help protect against heart disease and death.
Researchers say regular exercise may work by changing the body's metabolism not only to induce weight-loss but also help prevent fat accumulation in the stomach area.
"With this more efficient system, muscles can increase their use of lipid [fat] stores rather than relying primarily on carbohydrate reserves," says researcher Anne McTiernan, MD, PhD, of the Fred Hutchison Cancer Research Center in Seattle. "In addition, exercise helps counteract the weight regain often observed after diet-induced weight loss."
SOURCE: The Journal of the American Medical Association, Jan. 15, 2003.