Scheen A J, Luyckx A S, Fossion A, Lefebvre P J
Int J Obes. 1983;7(4):327-37.
This study aimed at investigating the influence of protein-supplemented fasting (PSF) on the tolerance and the fuel-hormone response to endurance exercise in the severely obese subject. For this purpose, eight obese men (27 +/- 2 yr, 182 +/- 7 per cent of ideal body weight) exercised on a horizontal treadmill (4 km/h) during 3 h before and after 13 d of PSF (Alburone, 70 g protein/day). Because of the 8.9 +/- 0.7 kg weight loss and the corresponding lower energy cost, exercise oxygen consumption decreased from 1.6 +/- 0.1 (before PSF) to 1.4 +/- 0.1 l/min (after PSF). In contrast, mean exercise heart rate was identical (119 +/- 5/min) in both conditions, resulting in a lower oxygen pulse after PSF. The mean respiratory quotient measured during exercise was lower after PSF (0.72 +/- 0.01 vs 0.75 +/- 0.01 2 P less than 0.05), thus demonstrating a higher fat utilization. This was supported by a higher exercise-induced plasma free fatty acid (FFA) mobilization after PSF (delta plasma FFA: + 675 +/- 101 vs + 376 +/- 121 mumol/l, 2 P less than 0.05). This metabolic adaptation mainly results from two mechanisms: a significantly lower plasma IRI at rest and during exercise after PSF (5.7 +/- 0.8 vs 11.4 +/- 1.4 microunits/ml, 2 P less than 0.001); and a lower basal blood glucose (4.2 +/- 0.2 vs 4.6 +/- 0.1 mmol/l) and an earlier decrease of glucose (30th vs 90th min) during exercise after PSF, suggesting a relative depletion of the carbohydrates stores. The lipolytic hormones (glucagon, epinephrine, norepinephrine, cortisol, growth hormone) did not significantly increase during exercise after PSF when compared to exercise before PSF; thus, their role in the enhanced FFA mobilization appears less important. Only two of our eight subjects were unable to achieve the third hour of exercise after PSF; however, no major clinical events or electrocardiographical disturbances were observed in any of the eight subjects. In conclusion, moderate exercise can be tolerated at least for 2 h during PSF when appropriate fluid, mineral and vitamin therapy is given. Under these conditions it induces a preferential utilization of fat-derived substrates and selectively augments fat mobilization which favors weight loss. For these reasons, moderate exercise can be recommended under strict medical supervision as part of all weight reduction therapy.
本研究旨在调查补充蛋白质的禁食（PSF）对重度肥胖受试者耐力运动耐受性及燃料-激素反应的影响。为此，8名肥胖男性（27±2岁，理想体重的182±7%）在接受13天的PSF（Alburone，每日70克蛋白质）前后，于水平跑步机上以4公里/小时的速度运动3小时。由于体重减轻了8.9±0.7千克以及相应较低的能量消耗，运动耗氧量从PSF前的1.6±0.1升/分钟降至PSF后的1.4±0.1升/分钟。相比之下，两种情况下的平均运动心率相同（119±5次/分钟），导致PSF后的氧脉搏较低。PSF后运动期间测得的平均呼吸商较低（0.72±0.01对0.75±0.01，P<0.05），从而表明脂肪利用率更高。这得到了PSF后更高的运动诱导血浆游离脂肪酸（FFA）动员的支持（血浆FFA变化：+675±101对+376±121微摩尔/升，P<0.05）。这种代谢适应主要源于两种机制：PSF后静息及运动期间血浆胰岛素抵抗指数显著降低（5.7±0.8对11.4±1.4微单位/毫升，P<0.001）；以及PSF后运动期间基础血糖较低（4.2±0.2对4.6±0.1毫摩尔/升）且葡萄糖下降更早（第30分钟对第90分钟），提示碳水化合物储备相对耗尽。与PSF前运动相比，PSF后运动期间脂解激素（胰高血糖素、肾上腺素、去甲肾上腺素、皮质醇、生长激素）并未显著增加；因此它们在增强FFA动员中的作用似乎不太重要。我们的8名受试者中只有2名在PSF后无法完成第三小时的运动；然而，8名受试者中均未观察到重大临床事件或心电图异常。总之，在给予适当的液体、矿物质和维生素治疗时，PSF期间至少2小时的适度运动是可以耐受的。在这些条件下，它会优先利用脂肪衍生的底物并选择性地增强脂肪动员，这有利于体重减轻。基于这些原因，在严格的医学监督下，适度运动可作为所有减肥疗法的一部分被推荐。
