Beneficial effects of exercise: shifting the focus from body weight to other markers of health
- 1 QUT, Australia;
- 2 Trinitu All Saints, United Kingdom;
- 3 University of Leeds, United Kingdom;
- 4 Slimming World, United Kingdom
- Correspondence to: neil king, Queensland University of Technology, IHBI, MUsk Av, Kelvin Grove, Brisbane, 4059, Australia;
- Received 13 August 2009
- Accepted 24 August 2009
- Published Online First 29 September 2009
Background: Exercise is widely promoted as a method of weight management, whilst the other health benefits are often ignored. The purpose of this study was to examine whether exercise-induced improvements in health are influenced by changes in body weight.
Methods: Fifty-eight sedentary overweight/obese men and women (BMI 31.8 ±4.5kg/m2) participated in a 12 week supervised aerobic exercise intervention (70% heart rate max, 5 times a week, 500kcal per session). Body composition, anthropometric parameters, aerobic capacity, blood pressure and acute psychological response to exercise were measured at weeks 0 and 12.
Results: Mean reduction in body weight was -3.3 ±3.63kg (P<0.01). However, 26 of the 58 participants failed to attain the predicted weight loss estimated from individuals’ exercise-induced energy expenditure. Their mean weight loss was only -0.9 ±1.8kg (P<0.01). Despite attaining lower than predicted weight reduction, these individuals experienced significant increases in aerobic capacity (6.3 ±6.0ml.kg-1.min-1; P<0.01), decreased systolic (-6.00 ±11.5mmHg; P<0.05) and diastolic blood pressure (-3.9 ±5.8mmHg; P<0.01), waist circumference (-3.7 ±2.7cm; P<0.01) and resting heart rate (-4.8±8.9bpm, p<0.001). In addition, these individuals experienced an acute exercise-induced increase in positive mood.
Conclusions: These data demonstrate that significant and meaningful health benefits can be achieved even in the presence of lower than expected exercise-induced weight loss. Less successful reduction in body weight does not undermine the beneficial effects of aerobic exercise. From a public health perspective, exercise should be encouraged and the emphasis on weight loss reduced.