The present study aimed to investigate whether nocturnal melatonin (MEL) ingestion has beneficial effects against exercise-induced oxidative stress and muscle damage in young athletes. Fourteen healthy-trained teenagers performed two-test sessions separated by at least, 1 week. During each session, participants completed the Running-Based Anaerobic Sprint Test (RAST) at 20:00 h. Then, they ingested a single 10-mg tablet of MEL or Placebo (PLA) in a double-blind randomized order at 22:00 h. The following morning (i.e., 07:30 h), participants performed the same test as the previous night. Blood samples were taken before and after exercise. MEL intake increased the peak power (Ppeak) (p < .01), mean power (Pmean) (p < .001) and decreased the total time (TT) (p < .001) and the fatigue index (FI) (p < .05). Furthermore, MEL ingestion attenuated the hematologic parameters before and after exercise (White Blood Cells (WBC: p < .001 and p < .001, respectively); Neutrophiles (NE: p < .001 and p < .001, respectively); Lymphocytes (LY: p < .001 and p < .001, respectively)) and the ultra-sensitive C-reactive protein (us-CRP: p < .001 and p < .001; respectively) compared to PLA. Also, MEL reduced muscle and hepatic damage enzymes before and after exercise (creatine kinase (CK: p < .001 and p < .001; respectively), lactate dehydrogenase (LDH: p < .05 and p < .01; respectively), aspartate aminotransferase (ASAT: p < .01 and p < .001; respectively)), Malondialdehyde (MDA: p < .001 and p < .001; respectively) and Homocysteine (Hcy: p < .001 and p < .001; respectively)) from placebo. Plasma lactate [La] and glucose (GL) remained unchangeable during the two conditions. In summary, acute MEL ingestion after strenuous late-evening exercise attenuated transient leucocytosis and protected against lipid peroxidation and muscle damage induced by strenuous exercise the following morning in healthy male teenage athletes.

中文翻译：

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晚上进行大量的深夜运动后，褪黑激素的摄入可在第二天的青少年运动员短期剧烈运动期间减轻肌肉损伤，氧化应激和炎症。

本研究旨在调查夜间褪黑激素（MEL）的摄入是否对运动引起的年轻运动员的氧化应激和肌肉损伤具有有益的作用。14名接受过健康训练的青少年进行了两次测试，每次间隔至少1周。在每个会话期间，参与者在20:00 h完成了基于跑步的厌氧冲刺测试（RAST）。然后，他们在22:00 h以双盲随机顺序摄入了10毫克的MEL或安慰剂（PLA）片剂。第二天早上（即07:30 h），参与者进行了与前一天晚上相同的测试。运动前后分别采集血样。摄入MEL可使峰值功率（Ppeak）（p <.01），平均功率（Pmean）（p <.001）和总时间（TT）（p <.001）和疲劳指数（FI）（p <.05）。此外，MEL摄入会减弱运动前后的血液学参数（白细胞（分别为WBC：p <.001和p <.001）；嗜中性粒细胞（NE：分别为p <.001和p <.001）；淋巴细胞（LY ：分别为p <.001和p <.001）和超敏感的C反应蛋白（us-CRP：p <.001和p <.001；分别与PLA相比）。而且，MEL降低了运动前后的肌肉和肝损伤酶（肌酸激酶（CK：p <.001和p <.001；分别），乳酸脱氢酶（LDH：p <.05和p <.01），天冬氨酸转氨酶（ASAT：p <.01和p <.001；分别），丙二醛（MDA：p <.001和p <.001；分别）和同型半胱氨酸（Hcy：p <.001和p <.001；分别））。在这两种情况下，血浆乳酸[La]和葡萄糖（GL）保持不变。总之，剧烈的傍晚运动后的急性MEL摄入可减轻健康的男性青少年运动员第二天早晨剧烈运动引起的脂质过氧化和暂时性白细胞增多，并防止脂质过氧化和肌肉损伤。