Commentaries on Viewpoint: Do oxidative and anaerobic energy production in exercising muscle change throughout growth and maturation? Aerobic deconditioning and gain in muscle mass during puberty rather than immature muscular glycolytic activity pre puberty.

摘要

Children's play is dominantly interval-sprint-like with activity bursts up to 15-s duration (1). Despite a decreasing volume of daily physical activity (4) maturation increases muscle mass and maximum short-term power substantially during puberty (5). Corresponding effects on anaerobic enzymes and maximum short-term performance related to muscle mass appear equivocal (2,5), but ratios of oxidative to anaerobic enzymes decrease (5), and the dynamics of oxygen uptake slows down (5). Although more or less unchanged if related to body mass, maximum oxygen uptake related to muscle mass decreases with increasing relative muscle mass during puberty. Also the relative body water content decreases (2). In children and adolescents the reliance on carbohydrate oxidation measured via indirect calorimetry is identically described as a function of the blood lactate concentration (BLC) up to an exercise intensity at which aerobic metabolism is almost fully reliant on carbohydrate oxidation (3).