Hynynen Esa, Uusitalo Arja, Konttinen Niilo, Rusko Heikki
KIHU-Research Institute for Olympic Sports, Jyväskylä, Finland.
Med Sci Sports Exerc. 2006 Feb;38(2):313-7. doi: 10.1249/01.mss.0000184631.27641.b5.
This study was conducted to test the hypothesis of autonomic imbalance in overtrained athletes during sleep and after awakening with analyses of heart rate variability (HRV) and nocturnal urine stress hormones.
We examined 12 athletes diagnosed to be severely overtrained (OA, 6 men and 6 women, mean age (+/-SD) 25 +/- 7 yr) and 12 control athletes (CA, 6 men and 6 women, mean age 24 +/- 5 yr). Overtraining diagnosis was further supported by higher perceived stress in OA than in CA (24.8 +/- 10.8 vs 15.3 +/- 5.5, P < 0.05). HRV was analyzed with time and frequency domain methods from RR intervals (RRI) recorded during sleep and after awakening. Nocturnal urine stress hormones were analyzed by liquid chromatography.
No differences were found in HRV or stress hormones during night sleep. After awakening, the standard deviation of RRI (84 +/- 31 vs 116 +/- 41 ms, P < 0.05) and low-frequency power of RRI (2153 +/- 2232 vs 4286 +/- 2904 ms, P < 0.05) were lower in OA than in CA. From sleep to after awakening, the coefficient of variation of RRI decreased more in OA than in CA (from 11.8 +/- 3.3 to 7.7 +/- 2.5%, P < 0.001 vs from 11.9 +/- 1.8 to 10.0 +/- 2.5%, P < 0.01, respectively, interaction P < 0.05).
The present findings suggest that in OA, cardiac autonomic modulation is at the level of control athletes during sleep, but the parasympathetic cardiac modulation is slightly diminished after awakening. Further investigations should concentrate on autonomic responses to different challenges, such as awakening in the present study.
本研究旨在通过分析心率变异性（HRV）和夜间尿应激激素，验证过度训练运动员在睡眠期间及醒来后的自主神经失衡假说。
我们检查了12名被诊断为严重过度训练的运动员（过度训练组，OA，6名男性和6名女性，平均年龄（±标准差）25±7岁）和12名对照运动员（对照组，CA，6名男性和6名女性，平均年龄24±5岁）。过度训练组的感知压力高于对照组（24.8±10.8对15.3±5.5，P<0.05），这进一步支持了过度训练的诊断。通过时域和频域方法，从睡眠期间和醒来后记录的RR间期（RRI）分析HRV。通过液相色谱法分析夜间尿应激激素。
夜间睡眠期间，HRV或应激激素未发现差异。醒来后，过度训练组的RRI标准差（84±31对116±41毫秒，P<0.05）和RRI低频功率（2153±2232对4286±2904毫秒，P<0.05）低于对照组。从睡眠到醒来后，过度训练组的RRI变异系数下降幅度大于对照组（分别从11.8±3.3降至7.7±2.5%，P<0.001；从11.9±1.8降至10.0±2.5%，P<0.01，交互作用P<0.05）。
目前的研究结果表明，在过度训练组中，睡眠期间心脏自主神经调节处于对照运动员的水平，但醒来后副交感神经心脏调节略有减弱。进一步的研究应集中在自主神经对不同挑战的反应上，如本研究中的醒来。
