Adipose tissue is loose connective tissue composed of adipocytes and originally derived from lipoblasts. Recently its critical role in the human body as a form of energy storage and endocrinological signaling has been recognized. Various physiological, psychosocial and clinical factors influence the amount and distribution of the adipose tissue throughout the human body. Lifestyle change in terms of increased physical activity and exercise is the best nonpharmacological treatment for obesity since these can reduce insulin resistance, counteract the inflammatory state, and improve the lipid profile. Physical activity and exercise are key components of energy expenditure and therefore of energy balance. Changes in energy balance alter fat mass. Physical activity influences adipose tissue both acutely and in the longer term. A single bout of exercise stimulates adipose tissue blood flow and fat mobilization, resulting in delivery of fatty acids to skeletal muscles at a rate well matched to metabolic requirements, except perhaps in vigorous intensity exercise. There is a period following an exercise bout when fatty acids are directed away from adipose tissue to other tissues such as skeletal muscle, reducing dietary fat storage in adipose. With chronic exercise (training), there are changes in adipose tissue physiology, particularly an enhanced fat mobilization during acute exercise. Epidemiological observations support the idea that physically active people have relatively low-fat mass, and intervention studies tend to show that exercise training reduces fat mass. A much-discussed effect of exercise versus calorie restriction in preferentially reducing visceral fat is not borne out by meta-analyses. We conclude that, in addition to the regulation of fat mass, physical activity may contribute to metabolic health through beneficial dynamic changes within adipose tissue in response to each activity bout.