Effects of sustained weight loss and exercise on aerobic fitness in obese women

Abstract

Objective: To assess the long term effects of weight loss with and without additional aerobic and weight training exercises on exercise tolerance and cardiorespiratory fitness in obese women.

Experimental design: Randomized prospective study for an approximately one-year community setting.

Patients: 31 healthy obese women volunteers (age 42.8 yrs +/- 6 SD) recruited by community advertisement.

Intervention: All subjects underwent a weight loss program consisting of low calorie diet and behavior therapy for a minimum of 46 weeks. They were randomly assigned to one of the four groups. Group A: diet alone, Group B: diet plus aerobic exercise program in a supervised group setting, Group C: Diet plus weight training and Group D: diet plus weight training plus aerobic exercise program.

Measures: Exercise time (Tex) peak sustained workload (Wp), peak oxygen consumption (VO2), oxygen pulse and the rate of change of VO2 on recovery (VO2rec) were measured at the beginning and after 47.5 weeks +/- 1.5 SD, of the program.

Results: All subjects lost weight and achieved increased Tex and lowered resting VO2. VO2 peak and VO2 peak kg-1 increase in Groups B and D only. O2 pulse and VO2rec improved in group D. Improvements in exercise time correlated significantly with initial exercise time and weight loss.

Conclusions: Weight loss increase Tex irrespective of participation in an exercise program. However, evidence of improved aerobic fitness occurred only in groups performing aerobic exercise.