Weltman A, Weltman J Y, Womack C J, Davis S E, Blumer J L, Gaesser G A, Hartman M L
Department of Human Services, Curry School of Education, Charlottesville, VA, USA.
Med Sci Sports Exerc. 1997 May;29(5):669-76. doi: 10.1097/00005768-199705000-00013.
To assess the influence of exercise training on the growth hormone (GH) response to acute exercise, six untrained males completed a 20-min, high-intensity, constant-load exercise test prior to and after 3 and 6 wk of training (the absolute power output (PO) during each test remained constant x PO = 182.5 +/- 29.5 W). Training increased (pre- vs post-training) oxygen uptake (VO2) at lactate threshold (1.57 +/- 0.33 L.min-1 vs 1.97 +/- 0.24 L.min-1 P < or = 0.05). VO2 at 2.5 mM blood lactate concentration ([HLa]) (1.83 +/- 0.38 L.min-1 vs 2.33 +/- 0.38 L.min-1, P < or = 0.05), and VO2peak (3.15 +/- 0.54 L.min-1 vs 3.41 +/- 0.47 L.min-1, P < or = 0.05). Power output at the lactate threshold (PO-LT) increased with training from 103 +/- 28 to 132 +/- 23W (P < or = 0.05). Integrated GH concentration (20 min exercise + 45 min recovery) (microgram.L-1 x min) after 3 wk (138 +/- 106) and 6 wk (130 +/- 145) were significantly lower (P < or = 0.05) than pre-training (238 +/- 145). Plasma epinephrine and norepinephrine responses to training were similar to the GH response (EPI-pre-training = 2447 +/- 1110; week 3 = 1046 +/- 144; week 6 = 955 +/- 322 pmol.L-1; P < or = 0.05; NE pre-training = 23.0 +/- 5.2; week 3 = 13.4 +/- 4.8; week 6 = 12.1 +/- 6.8 nmol.L-1; P < or = 0.05). These data indicate that the GH and catecholamine response to a constant-load exercise stimulus are reduced within the first 3 wk of exercise training and support the hypothesis that a critical threshold of exercise intensity must be reached to stimulate GH release.
为评估运动训练对生长激素（GH）急性运动反应的影响，6名未经训练的男性在训练3周和6周前后分别完成了一次20分钟的高强度、恒定负荷运动测试（每次测试期间的绝对功率输出（PO）保持恒定，PO = 182.5±29.5瓦）。训练后（训练前与训练后相比）乳酸阈时的摄氧量（VO2）增加（1.57±0.33升·分钟-1对1.97±0.24升·分钟-1，P≤0.05）。血乳酸浓度（[HLa]）为2.5毫摩尔时的VO2（1.83±0.38升·分钟-1对2.33±0.38升·分钟-1，P≤0.05）以及VO2峰值（3.15±0.54升·分钟-1对3.41±0.47升·分钟-1，P≤0.05）。乳酸阈时的功率输出（PO-LT）随着训练从103±28瓦增加到132±23瓦（P≤0.05）。3周（138±106）和6周（130±145）后20分钟运动+45分钟恢复后的GH综合浓度（微克·升-1×分钟）显著低于训练前（238±145）（P≤0.05）。血浆肾上腺素和去甲肾上腺素对训练的反应与GH反应相似（肾上腺素-训练前 = 2447±1110；第3周 = 1046±144；第6周 = 955±322皮摩尔·升-1；P≤0.05；去甲肾上腺素-训练前 = 23.0±5.2；第3周 = 13.4±4.8；第6周 = 12.1±6.8纳摩尔·升-1；P≤0.05）。这些数据表明，在运动训练的前3周内，对恒定负荷运动刺激的GH和儿茶酚胺反应降低，支持了必须达到一定运动强度阈值才能刺激GH释放的假说。
