Background:
The rates of morbid obesity are rising rapidly, and this increases the prevalence of physical disabilities during ageing. Weight loss will improve physical function. Exercise training added to diet for weight loss improves fitness for adults with overweight even when weight loss is modest, but evidence shows the exercise training response may be blunted in obesity. The purpose of this research was to determine whether a high volume of exercise training for women with clinically severe obesity leads to higher physical performance outcomes in the presence of an energy restricted diet.
Methods:
60 pre-menopausal women with clinically severe obesity were randomised to either energy restriction only or energy restriction plus 300 weekly minutes of exercise training (aerobic plus resistance training). Participants underwent testing at 0,3,6, and 12 months for VO2peak, muscular strength, and body composition.
Results:
Upper and lower body strength improved to a greater extent in the exercise training group compared to energy restriction only at all time points (p<0.05). Exercise training improved VO2peak more than Energy restriction at three (mean diff±SEM, 2.5ml.kg.min±0.9, p=0.006) and six months (3.1ml.kg.min±1.7, p=0.007), but not 12 months (mean diff±SEM, 2.3ml.kg.min±1.6, p=0.15). Exercise training facilitated fat mass loss at three months (mean diff±SEM, -5kg±2.5, p=0.047), six months (mean diff±SEM, -6.2kg±2.7, p=0.023), but not 12 months (mean diff±SEM, -3.9kg±2.8, p=0.16). There were no differences in lean mass loss at any timepoint.
Conclusion:
Exercise training improved physical performance and body composition at three and six months, but this is not maintained at 12 months. Interestingly, differences in strength continued at 12 months. This is important because strength is a critical factor in gait, activities of daily living, occupational demands and prevention of musculoskeletal injury. Our results suggest that resistance exercise may be an important method for enhancing physical function following intentional weight loss.