The consensus data suggest that physical activity benefits weight-related outcomes via its effect on altering energy balance. Therefore analyses of the impact of exercise on weight loss have shown that the extent of weight loss is dependent on the dose of exercise, with relatively small doses associated with little or no weight loss, but large doses capable of delivering significant weight loss provided they are adhered to and sustained. Around 300-420 minutes per week of moderate to vigorous intensity physical activity appears to be required for meaningful weight loss. The benefits are greater when combined with dietary restriction.
The high exercise volumes recommended for significant weight loss may not be possible, or difficult to achieve for some clientele, and the majority of the population fails to meet these levels. Furthermore, there is large inter-individual variability in weight loss resulting from exercise interventions. Given the benefits of increased physical activity on health, the simplest advice for many people may be that the more activity that is undertaken the better.
Increasing research interest has centred on the benefits of physical activity independent of weight loss, and the usefulness of low levels of exercise for health outcomes. Studies in previously inactive overweight/obese adults suggest that aerobic exercise training at doses below current recommendations is effective for improving fitness and reducing visceral and ‘ectopic’ adiposity, which are strongly associated with metabolic and cardiovascular disease risk. These benefits can occur independent of changes in body weight. Despite conferring other benefits, the utility of some physical activity approaches (e.g. high intensity interval exercise and resistance exercise) for adiposity management is less clear.