Kavouras Stavros A, Armstrong Lawrence E, Maresh Carl M, Casa Douglas J, Herrera-Soto Jorge A, Scheett Timothy P, Stoppani James, Mack Gary W, Kraemer William J
Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, USA.
J Appl Physiol (1985). 2006 Feb;100(2):442-50. doi: 10.1152/japplphysiol.00187.2005. Epub 2005 Oct 6.
The impact of rehydration with glycerol on cardiovascular and thermoregulatory responses during exercise in the heat was studied in eight highly trained male cyclists. Each subject completed three dehydration-rehydration experimental trials that differed only in the rehydration treatment, each separated by 7 days. Before each experimental day, subjects dehydrated to -4% of their body weight by exercise and water restriction. The experimental treatments were as follows: no fluid (NF), glycerol bolus (1 g/kg body wt) followed by water (G), and water alone (W). Rehydration (3% body weight) was given over an 80-min period. After rehydration, subjects cycled (74% peak O2 uptake) to exhaustion in a hot and wet (37 degrees C and 48% relative humidity) environment. For G, plasma volume was expanded (P < 0.05) during rehydration and remained higher than W (P < 0.05) during exercise. Exercise time to exhaustion during G (33 +/- 4 min) was longer (P < 0.05) compared with both W (27 +/- 3 min) and NF (19 +/- 3 min). Cutaneous vascular conductance was significantly elevated (P < 0.05) during G, but G provided no other thermoregulatory or cardiovascular benefits compared with W and NF. Fluid-regulating hormones (vasopressin, aldosterone, atriopeptin, and plasma renin activity) decreased during rehydration and increased during exercise (except atriopeptin), but there were no differences between G and W. These data indicated that glycerol had little or no major effect on fluid-regulating factors during rehydration or exercise, and the improved exercise capacity in G was likely due to a greater plasma volume during exercise.
在八名训练有素的男性自行车运动员中，研究了甘油补液对热环境下运动期间心血管和体温调节反应的影响。每位受试者完成了三项脱水 - 补液实验试验，这些试验仅在补液处理上有所不同，每次试验间隔7天。在每个实验日之前，受试者通过运动和限制饮水使体重减轻4%。实验处理如下：无补液（NF）、先给予甘油推注（1 g/kg体重）然后再饮水（G）、仅饮水（W）。在80分钟内给予补液（体重的3%）。补液后，受试者在炎热潮湿（37摄氏度和48%相对湿度）的环境中以74%的峰值摄氧量进行骑行直至力竭。对于G组，补液期间血浆量增加（P < 0.05），并且在运动期间保持高于W组（P < 0.05）。与W组（27 +/- 3分钟）和NF组（19 +/- 3分钟）相比，G组的运动至力竭时间更长（P < 0.05）。G组期间皮肤血管传导显著升高（P < 0.05），但与W组和NF组相比，G组未提供其他体温调节或心血管益处。补液期间液体调节激素（血管加压素、醛固酮、心房肽和血浆肾素活性）降低，运动期间升高（心房肽除外），但G组和W组之间没有差异。这些数据表明，甘油在补液或运动期间对液体调节因子几乎没有或没有主要影响，G组运动能力的提高可能是由于运动期间血浆量增加。
