Poehlman E T, Gardner A W, Arciero P J, Goran M I, Calles-Escandon J
Baltimore Veterans Affairs Medical Center, University of Maryland, Baltimore 21201.
J Appl Physiol (1985). 1994 Jun;76(6):2281-7. doi: 10.1152/jappl.1994.76.6.2281.
We examined the influence of 8 wk of endurance training on basal levels of fat oxidation and its association with changes in norepinephrine (NE) kinetics, resting metabolic rate (RMR), and body composition in 18 healthy elderly persons (66.1 +/- 1.4 yr; 10 men, 8 women). Fatty acid appearance rate and total body fat oxidation were determined from [14C]palmitate infusion and indirect calorimetry, NE kinetics were determined from infusions of [3H]NE, RMR was determined from the ventilated hood technique, and body composition was determined from underwater weighing. Endurance training increased peak oxygen consumption by 11% (1.9 +/- 0.1 to 2.1 +/- 0.1 l/min; P < 0.01) and increased RMR by 7% (1.20 +/- 0.02 to 1.28 +/- 0.02 kcal/min; P < 0.01). Endurance training increased NE appearance rate by 35% (0.51 +/- 0.04 to 0.69 +/- 0.04 micrograms/min; P < 0.01), whereas no change in NE clearance was noted. Endurance training increased fat oxidation by 22% (201.0 +/- 11.2 vs. 244.0 +/- 15.2 mumol/min; P < 0.01) but did not alter fatty acid appearance rate. Approximately two-thirds of the variation (r2 = 0.65) for the increase in fat oxidation was explained by increased NE appearance rate (r2 = 0.51; P < 0.01) and changes in fat-free weight (r2 = 0.14; P < 0.01). We conclude that 1) endurance training shifts in vivo basal substrate utilization toward greater fat oxidation in elderly individuals and 2) enhanced fat oxidation is associated with increased activity of the sympathetic nervous system and alterations in fat-free mass.
我们研究了8周耐力训练对18名健康老年人（66.1±1.4岁；10名男性，8名女性）基础脂肪氧化水平的影响，及其与去甲肾上腺素（NE）动力学、静息代谢率（RMR）和身体成分变化的关系。通过[14C]棕榈酸输注和间接量热法测定脂肪酸出现率和全身脂肪氧化，通过[3H]NE输注测定NE动力学，通过通风罩技术测定RMR，通过水下称重测定身体成分。耐力训练使峰值耗氧量增加了11%（从1.9±0.1升/分钟增加到2.1±0.1升/分钟；P<0.01），使RMR增加了7%（从1.20±0.02千卡/分钟增加到1.28±0.02千卡/分钟；P<0.01）。耐力训练使NE出现率增加了35%（从0.51±0.04微克/分钟增加到0.69±0.04微克/分钟；P<0.01），而NE清除率未见变化。耐力训练使脂肪氧化增加了22%（从201.0±11.2微摩尔/分钟增加到244.0±15.2微摩尔/分钟；P<0.01），但未改变脂肪酸出现率。脂肪氧化增加的约三分之二的变化（r2=0.65）可由NE出现率增加（r2=0.51；P<0.01）和去脂体重变化（r2=0.14；P<0.01）来解释。我们得出结论：1）耐力训练使老年人体内基础底物利用向更多的脂肪氧化转变；2）增强的脂肪氧化与交感神经系统活性增加和去脂体重改变有关。
