Shock horror: Exercise makes you feel better

A new study finds that — amazingly — exercising makes you feel better and improves your quality of life (QOL). The study found that this relationship was dose dependent: In other words, the more you exercise, the better you feel. (Obviously there’s a cutoff for this, but it’s a lot higher than most people would think.) Also noteworthy is the fact that it didn’t depend on weight loss, and that the study was done on previously sedentary postmenopausal women. (That would be many of YOU! So pay attention!)

Corby K. Martin, et al. Exercise Dose and Quality of Life: A Randomized Controlled Trial. Archives of Internal Medicine 2009;169(3):269-278.

Background: Improved quality of life (QOL) is a purported benefit of exercise, but few randomized controlled trials and no dose-response trials have been conducted to examine this assertion.

Methods The effect of 50%, 100%, and 150% of the physical activity recommendation on QOL was examined in a 6-month randomized controlled trial. Participants were 430 sedentary postmenopausal women (body mass index range, 25.0-43.0 [calculated as weight in kilograms divided by height in meters squared]) with elevated systolic blood pressure randomized to a nonexercise control group (n = 92) or 1 of 3 exercise groups: exercise energy expenditure of 4 (n = 147), 8 (n = 96), or 12 (n = 95) kilocalories per kilogram of body weight per week. Eight aspects of physical and mental QOL were measured at baseline and month 6 with the use of the Medical Outcomes Study 36-Item Short Form Health Survey.

Results Change in all mental and physical aspects of QOL, except bodily pain, was dose dependent (trend analyses were significant, and exercise dose was a significant predictor of QOL change; P < .05). Higher doses of exercise were associated with larger improvements in mental and physical aspects of QOL. Controlling for weight change did not attenuate the exercise-QOL association.

Conclusion Exercise-induced QOL improvements were dose dependent and independent of weight change.