Accumulating aerobic exercise for effective weight control.

PURPOSE

To compare the effects of different patterns of regular treadmill walking and cycle ergometry on body weight, body composition, waist and hip circumferences in overweight adult Singaporean females.

METHODS

Thirty overweight (BMI > 23 kg/m2) Singaporean females, aged 42.2 +/- 5.4 yr (mean +/- SD), all spasmodically physically active, were randomly assigned to two different eight-week programmes of aerobic exercise. One programme involved walking and cycling on indoor exercise machines at a moderate, comfortable intensity until 400 kcals had been expended, five times a week, thus giving a total weekly energy expenditure of 2,000 kcal. The other programme involved the same type of exercise but expending 1,000 kcal per session on two days a week, thereby giving the same weekly energy expenditure. Body weight, body mass index, body composition, waist and hip circumferences were measured before and after each programme. Prior to commencement of the study all subjects attended a one hour seminar on nutrition, health and fitness where the project structure was explained. They were asked not to change their eating habits during the intervention period and food diaries were kept and monitored weekly.

RESULTS

All subjects completed the eight-week programmes of exercise. Both programmes significantly reduced body weight, body mass index, percentage body fat and waist circumference (all p < 0.05). These reductions were identical in both the short-bout and long-bout programmes. No changes were observed in either group for hip circumference or lean body mass.

CONCLUSION

These findings demonstrated the effectiveness of moderate aerobic exercise in reducing body weight, body fat percentage and waist circumference whilst maintaining lean body mass in moderately overweight Singaporean females. The study also demonstrated that whether the exercise is performed in a series of short bouts five times a week or in longer bouts twice a week, the results are identical, providing that the total weekly energy expenditure remains the same.