Métabolisme lipidique et exercice musculaire chez le sujet obèse

Aims. - To estimate the effects of muscular exercise in obese. Current knowledge. - Even though muscular exercise allows only small weight loss, it results in an improvement of lipid metabolism. This might be explained by modifications of adipose tissue lipolysis and fat oxidation. The hormones involved in short-term lipolysis regulation are mainly the catecholamines, which can stimulate (beta-adrenergic receptors) and inhibit (alpha-adrenergic) it, the atrial natriuretic peptide (ANP), which activates lipolysis, and the insulin, which is the principal anti-lipolytic hormone. The alpha-adrenergic inhibiting effect increases with inactivity and BMI whereas the beta-adrenergic lipolytic effect rises during exercise, growing with its intensity and duration, resulting in increased lipid mobilization. Lipid oxidation increases with exercise duration. The intensity eliciting the maximal lipid oxidation increases with the fitness level. Endurance training leads to an increase in lipid mobilization due to beta-adrenergic and ANP-ergic sensitivity improvement and alpha-adrenergic effect reduction. Moreover, an increase in lipid oxidation ability appears in muscle. Therefore, endurance training leads to a better coordination between lipid mobilization and oxidation, which could contribute to reducing the metabolic consequences of obesity. (c) 2006 Elsevier SAS. Tous droits reserves.