Bahr R, Hansson P, Sejersted O M
Department of Physiology, National Institute of Occupational Health, Oslo, Norway.
Metabolism. 1990 Sep;39(9):993-9. doi: 10.1016/0026-0495(90)90313-2.
After exercise, there is a prolonged increase in O2 consumption termed the excess postexercise O2 consumption (EPOC). In this study, we have assessed the relative contribution of the triglyceride/fatty acid (TG/FA) substrate cycle to EPOC. Six healthy, young men exercised for 2 hours at 51% of maximal O2 uptake. The total energy expenditure and the rate of FA oxidation were estimated from measurements of O2 uptake, respiratory exchange ratio, and urinary nitrogen excretion while the subjects rested in bed for 3.5 hours postexercise. During the last part of the recovery period, the rate of FA mobilization was determined by infusion of glycerol. The rate of TG/FA cycling was calculated from the difference between the rate of FA mobilization and oxidation. An identical control study without exercise was also performed. The total EPOC during the recovery period was 7.82 +/- 1.51 L O2 (a 15% +/- 3% increase above the control O2 consumption). The rate of FA oxidation increased from 252 +/- 36 mumol/min (control) to 360 +/- 27 mumol/min (3 hours postexercise). The rate of FA mobilization increased from 666 +/- 108 mumol/min (control) to 1833 +/- 456 mumol/min (3 hours postexercise). TG/FA cycling was found to increase from 414 +/- 90 mumol FA/min (control) to 1473 +/- 435 mumol FA/min (3 hours postexercise). The energy cost of these rates of TG/FA cycling was found to be 0.09 +/- 0.02 kJ/min (control) and 0.31 +/- 0.09 kJ/min (3 hours postexercise). It is concluded that the energy cost of the increased TG/FA cycling rate may account for as much as half of the delayed component of EPOC.
运动后，氧气消耗量会有一段持续增加的时期，称为运动后过量氧耗（EPOC）。在本研究中，我们评估了甘油三酯/脂肪酸（TG/FA）底物循环对EPOC的相对贡献。六名健康的年轻男性以最大摄氧量的51%进行了2小时的运动。在运动后受试者卧床休息3.5小时期间，通过测量摄氧量、呼吸交换率和尿氮排泄来估计总能量消耗和脂肪酸氧化速率。在恢复期的最后阶段，通过输注甘油来测定脂肪酸动员速率。TG/FA循环速率由脂肪酸动员速率和氧化速率之差计算得出。还进行了一项相同的无运动对照研究。恢复期的总EPOC为7.82±1.51升氧气（比对照氧气消耗量增加15%±3%）。脂肪酸氧化速率从252±36微摩尔/分钟（对照）增加到360±27微摩尔/分钟（运动后3小时）。脂肪酸动员速率从666±108微摩尔/分钟（对照）增加到183³±456微摩尔/分钟（运动后3小时）。发现TG/FA循环从414±90微摩尔脂肪酸/分钟（对照）增加到1473±435微摩尔脂肪酸/分钟（运动后3小时）。这些TG/FA循环速率的能量消耗在对照时为0.09±0.02千焦/分钟，在运动后3小时为0.31±0.09千焦/分钟。结论是，TG/FA循环速率增加的能量消耗可能占EPOC延迟部分的多达一半。
