Effects of physical activity on weight reduction in obese middle-aged women.

Increased physical activity consisting of jog-walking 2.5 miles and 1 hr of calisthenics/week was the primary focus of a 17-week weight reduction program in 22 obese (X = 40% body fat) women ages 30 to 52, many of whom had failed at previous attempts to lose weight by dieting alone. Regular exercise was also increased substantially on an individual basis. Caloric restriction was self-determined and was generally moderate, accounting for about 60% of the total mean energy deficit. Initial and final evaluations included body composition by hydrostatic weighing, progressive multistage exercise testing, and plasma lipid and lipoprotein analyses. A mean relative body fat reduction of 5% (P less than or equal to 0.001) was achieved by a drop in fat body weight (X = 5.4 kg; P less than or equal to 0.001) which closely paralleled that of total body weight (X = 4.2 kg; P less than or equal to 0.001). Mean heart rates and systolic blood pressures at identical submaximal exercise intensities were significantly lower at the time of reevaluation. Mean plasma triglyceride and total cholesterol concentrations did not change significantly (P greater than 0.05). However, the high-density lipoprotein cholesterol/low-density lipoprotein cholesterol ratio increased significantly (P less than or equal to 0.05). Increased physical activity combined with moderate dieting is a feasible approach to weight reduction in middle-aged women.