The Florida State University, Department of Nutrition, Food and Exercise Sciences, Tallahassee, FL 32306-1493, USA.
Int J Sports Med. 2010 Feb;31(2):95-100. doi: 10.1055/s-0029-1242809. Epub 2009 Dec 17.
The purpose of the present study was to test if a previous acute concentric exercise bout blunts hGH response after an eccentric exercise bout. Nine healthy untrained male university students (25.4+/-0.5 yr, 176.5+/-1.2 cm, and 79.4+/-2.0 kg) performed a concentric exercise bout followed by an eccentric exercise bout one week later. Serum human growth hormone (hGH), creatine kinase (CK), and lactate were measured before, immediately and up to 32 h after both exercise bouts. Higher lactate values were observed immediately, 5 and 10 min after the concentric bout (70%, 119%, and 142%, respectively, p<0.05) than the eccentric bout. There was a CK main time effect at 8 and 32 h after the exercise bouts compared to baseline values (p<0.002). However, peak serum CK effect size was higher after the concentric than the eccentric exercise bout, 1.3 and 0.9, respectively. hGH increased after both exercise bouts, however it reached significance only at immediately (207%), 5 min (256%), 10 min (276%), 20 min (300%), and 40 min (168%) after the concentric exercise bout (p<0.05). Our findings suggest that a previous concentric exercise bout may blunt the anabolic response expected after an eccentric exercise bout.
本研究旨在测试先前的一次向心运动是否会使随后的离心运动后的 hGH 反应减弱。九名健康的未经训练的男性大学生（25.4+/-0.5 岁，176.5+/-1.2 厘米，79.4+/-2.0 公斤）进行了一次向心运动，一周后又进行了一次离心运动。在两次运动前后，分别测量血清人类生长激素（hGH）、肌酸激酶（CK）和乳酸。与离心运动相比，向心运动后即刻、5 分钟和 10 分钟时，乳酸值分别升高了 70%、119%和 142%（p<0.05）。与基线值相比，运动后 8 小时和 32 小时，CK 有主要时间效应（p<0.002）。然而，向心运动后的血清 CK 峰值效应大小高于离心运动，分别为 1.3 和 0.9。两种运动后 hGH 均升高，但仅在向心运动后即刻（207%）、5 分钟（256%）、10 分钟（276%）、20 分钟（300%）和 40 分钟（168%）时具有统计学意义（p<0.05）。我们的研究结果表明，先前的向心运动可能会使随后的离心运动后的合成代谢反应减弱。
