Dose-response to exercise: modest exercise maintains weight in mildly obese.(Clinical Rounds)

About 30 minutes of brisk walking each day can help maintain weight in overweight and mildly obese people who continue their normal eating pattern, reported Cris A. Slentz, Ph.D., and colleagues at Duke University, Durham, N.C.

A total of 120 sedentary men and women aged 40-65 years (average age 53 years) with mild to moderate dyslipidemia completed the study. Subjects were randomized to either no exercise (control group) or one of three different exercise regimens: low amount of activity at moderate intensity, low amount of activity at vigorous intensity, or high amount of activity at vigorous intensity.

Moderate-intensity exercise was defined as moderate to brisk walking or its equivalent, whereas vigorous exercise was jogging or its equivalent. The study began with a ramp-up period of 2-3 months, during which subjects reached the appropriate exercise level. Thereafter, they continued their exercise regimen for 6 months without altering their caloric intake from baseline levels (Arch. Intern. Med. 164[1]:31-39, 2004).

The effect of the amount of exercise on 12 different variables that measured body weight and body composition consistently followed a dose-response relationship. For all of these variables, except for the change in lean body mass, the 27 individuals in the group who exercised a high amount had significant improvements, compared with the 37 ...