Romijn J A, Klein S, Coyle E F, Sidossis L S, Wolfe R R
Department of Internal Medicine, University of Texas Medical Branch, Galveston.
J Appl Physiol (1985). 1993 Jul;75(1):108-13. doi: 10.1152/jappl.1993.75.1.108.
Basal whole body lipid kinetics were evaluated in nine endurance-trained cyclists and 10 untrained healthy controls. The rate of appearance (Ra) of glycerol (an index of whole body lipolysis), the Ra of palmitate (an index of fatty acid release), and the rate of triglyceride-fatty acid cycling (reesterification of fatty acids released during lipolysis) were determined by infusing [2H5]glycerol and [2H2]palmitate in conjunction with indirect calorimetry. All subjects were studied while they were at rest after fasting overnight. Glycerol Ra and free fatty acid Ra in the athletes (7.33 +/- 0.68 and 14.88 +/- 1.35 mumol.kg-1 x min-1, respectively) were two- to threefold higher than the values in untrained control subjects (2.53 +/- 0.15 and 7.64 +/- 0.92 mumol.kg-1 x min-1, respectively; P < 0.02). The total rate of triglyceride-fatty acid cycling was approximately four-fold higher in the athletes (16.86 +/- 2.07 mumol.kg-1 x min-1) than in the control subjects (3.91 +/- 0.36 mumol.kg-1 x min-1). Plasma concentrations of insulin and catecholamines, hormones that regulate whole body lipid kinetics, were the same in both groups. We conclude that resting basal lipid kinetics are markedly increased in athletes involved in strenuous endurance training and that this enhances the potential for increasing fatty acid oxidation rapidly at the onset of exercise.
对9名耐力训练的自行车运动员和10名未经训练的健康对照者进行了基础全身脂质动力学评估。通过输注[2H5]甘油和[2H2]棕榈酸酯并结合间接量热法，测定甘油的出现率（Ra）（全身脂肪分解的指标）、棕榈酸酯的Ra（脂肪酸释放的指标）以及甘油三酯 - 脂肪酸循环率（脂肪分解过程中释放的脂肪酸的再酯化）。所有受试者在禁食过夜后休息时进行研究。运动员的甘油Ra和游离脂肪酸Ra（分别为7.33±0.68和14.88±1.35μmol·kg-1×min-1）比未经训练的对照受试者的值（分别为2.53±0.15和7.64±0.92μmol·kg-1×min-1）高两到三倍（P<0.02）。运动员的甘油三酯 - 脂肪酸循环总速率（16.86±2.07μmol·kg-1×min-1）比对照受试者（3.91±0.36μmol·kg-1×min-1）高约四倍。两组中调节全身脂质动力学的激素胰岛素和儿茶酚胺的血浆浓度相同。我们得出结论，参与剧烈耐力训练的运动员静息基础脂质动力学显著增加，这增强了运动开始时快速增加脂肪酸氧化的潜力。
