Kraemer William J, Spiering Barry A, Volek Jeff S, Ratamess Nicholas A, Sharman Matthew J, Rubin Martyn R, French Duncan N, Silvestre Ricardo, Hatfield Disa L, Van Heest Jaci L, Vingren Jakob L, Judelson Daniel A, Deschenes Michael R, Maresh Carl M
Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269-1110, USA.
Med Sci Sports Exerc. 2006 Jul;38(7):1288-96. doi: 10.1249/01.mss.0000227314.85728.35.
The purpose of this investigation was to determine the effects of 3 wk of L-carnitine L-tartrate (LCLT) supplementation and post-resistance-exercise (RE) feeding on hormonal and androgen receptor (AR) responses.
Ten resistance-trained men (mean+/-SD: age, 22+/-1 yr; mass, 86.3+/-15.3 kg; height, 181+/-11 cm) supplemented with LCLT (equivalent to 2 g of L-carnitine per day) or placebo (PL) for 21 d, provided muscle biopsies for AR determinations, then performed two RE protocols: one followed by water intake, and one followed by feeding (8 kcal.kg body mass, consisting of 56% carbohydrate, 16% protein, and 28% fat). RE protocols were randomized and included serial blood draws and a 1-h post-RE biopsy. After a 7-d washout period, subjects crossed over, and all experimental procedures were repeated.
LCLT supplementation upregulated (P<0.05) preexercise AR content compared with PL (12.9+/-5.9 vs 11.2+/-4.0 au, respectively). RE increased (P<0.05) AR content compared with pre-RE values in the PL trial only. Post-RE feeding significantly increased AR content compared with baseline and water trials for both LCLT and PL. Serum total testosterone concentrations were suppressed (P<0.05) during feeding trials with respect to corresponding water and pre-RE values. Luteinizing hormone demonstrated subtle, yet significant changes in response to feeding and LCLT.
In summary, these data demonstrated that: 1) feeding after RE increased AR content, which may result in increased testosterone uptake, and thus enhanced luteinizing hormone secretion via feedback mechanisms; and 2) LCLT supplementation upregulated AR content, which may promote recovery from RE.
本研究旨在确定补充3周L-肉碱酒石酸盐（LCLT）以及抗阻运动（RE）后进食对激素和雄激素受体（AR）反应的影响。
10名进行抗阻训练的男性（平均±标准差：年龄，22±1岁；体重，86.3±15.3千克；身高，181±11厘米）补充LCLT（相当于每天2克L-肉碱）或安慰剂（PL）21天，提供肌肉活检样本用于AR测定，然后进行两种RE方案：一种之后饮水，另一种之后进食（8千卡·千克体重，由56%碳水化合物、16%蛋白质和28%脂肪组成）。RE方案随机安排，包括系列采血和RE后1小时的活检。经过7天的洗脱期后，受试者交叉进行，所有实验程序重复进行。
与PL相比，补充LCLT使运动前AR含量上调（P<0.05）（分别为12.9±5.9和11.2±4.0任意单位）。仅在PL试验中，RE使AR含量相对于RE前值增加（P<0.05）。与基线以及LCLT和PL的饮水试验相比，RE后进食显著增加了AR含量。在进食试验期间，血清总睾酮浓度相对于相应的饮水和RE前值受到抑制（P<0.05）。促黄体生成素在对进食和LCLT的反应中表现出细微但显著的变化。
总之，这些数据表明：1）RE后进食增加了AR含量，这可能导致睾酮摄取增加，从而通过反馈机制增强促黄体生成素的分泌；2）补充LCLT上调了AR含量，这可能促进从RE中恢复。
