Kenefick R W, Maresh C M, Armstrong L E, Castellani J W, Whittlesey M, Hoffman J R, Bergeron M F
The University of Connecticut, Human Performance Laboratory, Department of Sport, Leisure, and Exercise Science, Storrs 06269-1110, USA.
Int J Sports Med. 1998 Apr;19(3):177-81. doi: 10.1055/s-2007-971900.
Seven endurance-trained and heat-nonacclimated men (Mean+/-SEM: 20+/-1 yr; VO2max = 67+/-2 ml x kg(-1) x min(-1)) ran in two environments (M: 23 degrees C, H: 38 degrees C; 7 days apart) at two absolute training-intensity velocities (S1: 240 m x min(-1); followed by S2: 270 m x min(-1); 10 min each) during the winter months. Blood samples were taken via cannula before (pre) S1 and after S1 and S2. Plasma testosterone (TEST) concentrations increased (p<0.05) above pre levels after S1 in M (19+/-3 versus 24+/-3 nmol x L(-1)) and H (18+/-2 versus 23+/-3 nmol x L(-1)), and after S2 in H (18+/-2 versus 24+/-1 nmol x L(-1)). Plasma cortisol (CORT) and the molar ratio of TEST/CORT were unchanged from pre levels after S1 and S2 during M and H. No differences were found in plasma TEST, CORT, or the molar ratio of TEST/CORT between M and H. These results indicated that circulating levels of TEST and CORT were not changed in endurance-trained, heat-nonacclimated athletes in response to short-duration running performed at the same absolute intensity in the heat, compared to mild environmental conditions. The lack of significant differences in the molar ratio of TEST/CORT, between the 23 degrees C and 38 degrees C trials, suggested that this short-duration exercise challenge performed in the heat was no more of an anabolic or catabolic stimulus for these athletes.
七名经过耐力训练但未适应热环境的男性（平均±标准误：20±1岁；最大摄氧量=67±2毫升·千克⁻¹·分钟⁻¹）在冬季的两个环境中（M：23摄氏度，H：38摄氏度；间隔7天），以两种绝对训练强度速度（S1：240米·分钟⁻¹；随后是S2：270米·分钟⁻¹；各10分钟）跑步。在S1之前（预）、S1之后以及S2之后通过插管采集血样。在M环境中，S1之后血浆睾酮（TEST）浓度高于预水平（p<0.05）（19±3对24±3纳摩尔·升⁻¹），在H环境中S1之后（18±2对23±3纳摩尔·升⁻¹），在H环境中S2之后（18±2对24±1纳摩尔·升⁻¹）。在M和H环境中，S1和S2之后血浆皮质醇（CORT）以及TEST/CORT的摩尔比与预水平相比没有变化。在M和H环境之间，血浆TEST、CORT或TEST/CORT的摩尔比没有差异。这些结果表明，与温和环境条件相比，经过耐力训练、未适应热环境的运动员在炎热环境中以相同绝对强度进行短时间跑步后，循环中的TEST和CORT水平没有变化。在23摄氏度和38摄氏度试验之间，TEST/CORT的摩尔比缺乏显著差异，这表明在炎热环境中进行的这种短时间运动挑战对这些运动员而言，其合成代谢或分解代谢刺激并不更强。
