Lipid metabolism and muscular exercise in obese

• Published in: Science & sports 2006-04, Vol.21 (2), p.68-73
• Main Authors: Garrigue, E, De Glisezinski, I, Harant, I, Moro, C, Pillard, F, Crampes, F, Riviere, D
• Format: Article
• Language: eng ; fre
• ISSN: 0765-1597
• DOI: 10.1016/j.scispo.2005.06.011

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.Original Abstract: Objectifs Apprecier les effets de l'exercice physique chez le sujet obese. Donnees actuelles Meme si l'exercice musculaire n'entraine qu'une faible reduction ponderale, il permet d'ameliorer le metabolisme des lipides. Cela peut etre explique par des modifications de la lipolyse du tissu adipeux et de l'oxydation lipidique. Les hormones impliquees dans la regulation de la lipolyse a court terme sont principalement les catecholamines, qui peuvent la stimuler (recepteurs beta -adrenergiques) et l'inhiber (recepteurs alpha -adrenergiques), le peptide atrial natriuretique (ANP) qui l'active, et l'insuline qui est la principale hormone antilipolytique. L'effet inhibiteur alpha -adrenergique augmente avec l'IMC et le niveau de sedentarite. L'effet lipolytique beta -adrenergique augmente durant l'exercice, d'autant plus qu'il est intense et se prolonge, resultant en une augmentation de la mobilisation lipidique. L'oxydation des lipides augmente avec la duree de l'exercice, et l'intensite permettant une oxydation lipidique maximale augmente avec le niveau d'entrainement d'un sujet. L'entrainement en endurance permet d'a