Romijn J A, Coyle E F, Sidossis L S, Gastaldelli A, Horowitz J F, Endert E, Wolfe R R
Metabolism Unit, Shriners Burns Institute, University of Texas Medical Branch, Galveston 77550.
Am J Physiol. 1993 Sep;265(3 Pt 1):E380-91. doi: 10.1152/ajpendo.1993.265.3.E380.
Stable isotope tracers and indirect calorimetry were used to evaluate the regulation of endogenous fat and glucose metabolism in relation to exercise intensity and duration. Five trained subjects were studied during exercise intensities of 25, 65, and 85% of maximal oxygen consumption (VO2max). Plasma glucose tissue uptake and muscle glycogen oxidation increased in relation to exercise intensity. In contrast, peripheral lipolysis was stimulated maximally at the lowest exercise intensity, and fatty acid release into plasma decreased with increasing exercise intensity. Muscle triglyceride lipolysis was stimulated only at higher intensities. During 2 h of exercise at 65% VO2max plasma-derived substrate oxidation progressively increased over time, whereas muscle glycogen and triglyceride oxidation decreased. In recovery from high-intensity exercise, although the rate of lipolysis immediately decreased, the rate of release of fatty acids into plasma increased, indicating release of fatty acids from previously hydrolyzed triglycerides. We conclude that, whereas carbohydrate availability is regulated directly in relation to exercise intensity, the regulation of lipid metabolism seems to be more complex.
使用稳定同位素示踪剂和间接量热法来评估内源性脂肪和葡萄糖代谢与运动强度和持续时间相关的调节情况。对五名受过训练的受试者在最大耗氧量（VO2max）的25%、65%和85%的运动强度下进行了研究。血浆葡萄糖组织摄取和肌肉糖原氧化随运动强度增加而增加。相反，外周脂肪分解在最低运动强度下受到最大刺激，并且随着运动强度增加，脂肪酸释放到血浆中的量减少。肌肉甘油三酯分解仅在较高强度下受到刺激。在以65%VO2max进行2小时运动期间，血浆衍生底物氧化随时间逐渐增加，而肌肉糖原和甘油三酯氧化减少。在高强度运动恢复过程中，尽管脂肪分解速率立即下降，但脂肪酸释放到血浆中的速率增加，表明脂肪酸从先前水解的甘油三酯中释放出来。我们得出结论，虽然碳水化合物的可用性直接与运动强度相关调节，但脂质代谢的调节似乎更为复杂。
