Rietjens G J W M, Kuipers H, Adam J J, Saris W H M, van Breda E, van Hamont D, Keizer H A
Department of Movement Sciences, Maastricht University, Maastricht, The Netherlands.
Int J Sports Med. 2005 Jan-Feb;26(1):16-26. doi: 10.1055/s-2004-817914.
The purpose of the study was to investigate whether severe fatigue, possibly leading to overreaching, could be diagnosed at an early stage by a combination of parameters. Seven well-trained male subjects (age [mean +/- SD]: 25.3 +/- 4.7 yr; body mass: 76 +/- 6.6 kg; VO2max: 61.1 +/- 7 ml.kg(-1).min(-1)) increased their training load by doubling their training volume and increasing the intensity by 15 % over a period of two weeks. Before and after this intensified training period subjects underwent a series of tests including a maximal incremental cycle ergometer test (Wmax) with continuous ventilatory measurements and blood lactate values, time trial, basal blood parameter tests (red and white blood profile), hormones [growth hormone (GH), insulin-like growth factor 1(IGF-1), adreno-corticotropic hormone (ACTH), cortisol], neuro-endocrine stress test [short insulin tolerance test (SITT), combined anterior pituitary test (CAPT) and exercise], a shortened Profile of Mood State (POMS), the estimated rate of perceived exertion (RPE) and a cognitive reaction time test. The intensified training period resulted in a significant increase of the training load (p <0.01), training monotony (p <0.01) and training strain (p <0.01). The RPE during training increased significantly (p <0.01) during the intensified training period. Total mood score obtained from the POMS tended to increase (p=0.06), reflecting an increase in worse mood state. A novel finding was that reaction times increased significantly, indicating that overreaching might adversely affect speed of information processing by the brain, especially for the most difficult conditions. After the intensified training period, neither changes in exercise-induced plasma hormone values, nor SITT values were observed. During the CAPT only cortisol showed a significant decrease after the intensified training period. Hemoglobin showed a significant decrease after the intensified training period whereas hematocrit, red blood cell count (RBC) and MCV tended to decrease. The intensified training had no effect on physical performance (Wmax or time trial), maximal blood lactate, maximal heart rate and white blood cell profile. The most sensitive parameters for detecting overreaching are reaction time performance (indicative for cognitive brain functioning), RPE and to a lesser extend the shortened POMS. This strongly suggests, that central fatigue precedes peripheral fatigue. All other systems,including the neuro-endocrine, are more robust and react most likely at a later stage in exhaustive training periods.
本研究的目的是调查严重疲劳（可能导致过度训练）能否通过多种参数组合在早期阶段被诊断出来。七名训练有素的男性受试者（年龄[平均值±标准差]：25.3±4.7岁；体重：76±6.6千克；最大摄氧量：61.1±7毫升·千克⁻¹·分钟⁻¹）在两周内将训练量翻倍并将强度提高15%，从而增加了训练负荷。在这个强化训练期之前和之后，受试者接受了一系列测试，包括带有连续通气测量和血乳酸值的最大递增式自行车测力计测试（最大功率）、计时赛、基础血液参数测试（红细胞和白细胞指标）、激素[生长激素（GH）、胰岛素样生长因子1（IGF-1）、促肾上腺皮质激素（ACTH）、皮质醇]、神经内分泌应激测试[短胰岛素耐量测试（SITT）、联合垂体前叶测试（CAPT）和运动]、简化版情绪状态量表（POMS）、主观用力感觉率（RPE）估计值以及认知反应时间测试。强化训练期导致训练负荷（p<0.01）、训练单调性（p<0.01）和训练压力（p<0.01）显著增加。强化训练期内训练期间的RPE显著增加（p<0.01）。从POMS获得的总情绪得分有增加趋势（p=0.06），反映出情绪状态变差。一个新发现是反应时间显著增加，这表明过度训练可能会对大脑信息处理速度产生不利影响，尤其是在最困难的情况下。强化训练期之后，未观察到运动诱导的血浆激素值或SITT值的变化。在CAPT期间，强化训练期之后只有皮质醇显著下降。强化训练期之后血红蛋白显著下降，而血细胞比容、红细胞计数（RBC）和平均红细胞体积有下降趋势。强化训练对身体性能（最大功率或计时赛）、最大血乳酸、最大心率和白细胞指标没有影响。检测过度训练最敏感的参数是反应时间表现（指示认知脑功能）、RPE，以及在较小程度上是简化版POMS。这强烈表明，中枢疲劳先于外周疲劳出现。所有其他系统，包括神经内分泌系统，更具耐受性，最有可能在力竭训练期的后期做出反应。
