ABSTRACT
Increased physical activity alone can induce some reduction of body fat content, and the extent of benefit is greater than indicated by the decrease in body mass, since (in contrast to dieting) fat is often replaced by lean tissue. However, the necessary volume of physical activity is greater than that found in public health recommendations for general health. Given an adequate total volume of physical activity, a substantial fat loss can be achieved by either organized or incidental increases in physical activity. An inadequate volume of activity and/or an increased intake of food seem to be the main explanations of why some programmes have failed to achieve the desired results. If rigorous dieting has been implemented, exercise adds only slightly to the decrease of body mass, but importantly it helps conserve lean tissue. Aerobic exercise generally reduces body fat more than strength training, but resistance exercise is more effective in conserving lean tissue. In a long-term perspective, the most effective approach may be to incorporate greater physical activity into the daily routine. Exercise seems more effective than dieting in the long-term maintenance of weight loss Exercise also carries incidental advantages not realized with dieting, including improved psychological health, enhanced cardio-respiratory fitness, and the maintenance of muscle strength.
