February 13 (HealthDay News) -- Even if it doesn't help them lose weight, exercise can improve postmenopausal women's quality of life, a U.S. study shows.

It included 430 sedentary postmenopausal women (average age 57.4) randomly assigned to a non-exercise control group or one of three exercise groups: an exercise expenditure of 4 kilocalories per kilogram (2.2 pounds) of body weight per week (4-KKW), 8-KKW, or 12-KKW. Those levels represent 50 percent, 100 percent and 150 percent, respectively, of current public health physical activity recommendations.

"Adherence to exercise was 95.4 percent, 88.1 percent, and 93.7 percent for the 4-, 8- and 12-KKW groups, respectively, and each group spent 73.9, 138.3, and 183.6 minutes per week exercising," wrote Corby K. Martin, of the Pennington Biomedical Research Center and Louisiana State University System in Baton Rouge, La., and colleagues.

Average weight loss was: control group, 2.07 pounds; 4-KKW group, 2.95 pounds; 8-KKW group, 4.10 pounds; 12-KKW group, 2.95 pounds.

"A dose-response effect of exercise on quality of life was noted for all aspects of quality of life except bodily pain. In addition, the 4-KKW group had significantly improved general health perception, vitality and mental health compared with the control group. All three exercise groups had significantly improved social functioning compared with the control group," the researchers wrote.

The study was published in the Feb. 9 issue of the Archives of Internal Medicine.

"Our results indicate that improved quality of life can be added to the list of exercise benefits and that these improvements are dose dependent and independent of weight loss, at least among people similar to this study's sample," the authors wrote. "The exercise doses are easily obtainable and were well-tolerated by sedentary women, resulting in confidence that the exercise doses used in this study can be achieved by women in the community."

SOURCE: JAMA/Archives journals, news release, Feb. 9, 2009