Purpose

Circadian rhythm affects maximal short-term performance, and it is an important determinant of the training component. This review aimed to summarise the influence of circadian rhythm on peak and mean power output of muscle, fatigue index, and blood lactate levels.

Methods

English language articles were searched through the following databases: PubMed, Web of Science, Science Direct, and Google Scholar, and pertinent randomized control trials were scrutinized.

Results

The search revealed 17,481 articles, and 29 were included in this systematic review based on inclusion and exclusion criteria. Randomized control trials were selected, and the methodological validity of articles was evaluated using the ‘Cochrane risk of bias tool’. Findings suggest that outcome variables muscle peak power output (p < 0.0001, Z = 7.22, I² = 57.42, SMD = − 0.91, 95% confidence interval CI = − 1.16, − 0.67), muscle mean power output (p < 0.0001, Z = 5.66, I² = 83.85, SMD = − 0.75, 95% CI = − 1.01, − 0.49), and fatigue index (p = 0.02, Z = 2.41, I² = 2.49, SMD = − 0.39, 95% CI = − 0.72, − 0.07) were higher in the evening while the level of blood lactate was higher in the morning (p = 0.79, Z = 0.27, I² = 0.73, SMD = − 0.05, 95% CI = − 0.46, − 0.35).

Conclusion

The results show that diurnal variation affects both peak and mean power output of muscle as well as fatigue index. However, there is no remarkable effect of circadian rhythm on blood lactate level. A major factor attributed to this finding was the variation in the training experience of participants. For an effective training prescription, it is very important to consider the effect of the biological clock on muscle power output since anaerobic exercise performance is discernibly influenced by the time of the day.

中文翻译：

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昼夜节律对无氧性能和血乳酸水平的影响：系统评价

目的

昼夜节律影响最大的短期表现，它是训练组成部分的重要决定因素。本综述旨在总结昼夜节律对肌肉峰值和平均功率输出、疲劳指数和血乳酸水平的影响。

方法

通过以下数据库搜索英语文章：PubMed、Web of Science、Science Direct 和 Google Scholar，并仔细审查了相关的随机对照试验。

结果

搜索结果显示 17,481 篇文章，其中 29 篇根据纳入和排除标准被纳入该系统评价。选择了随机对照试验，并使用“Cochrane 偏倚风险工具”评估了文章的方法学有效性。结果表明，结果变量肌肉峰值功率输出（p  < 0.0001，Z  = 7.22，I ²  = 57.42，SMD = − 0.91，95% 置信区间 CI = − 1.16，− 0.67），肌肉平均功率输出（p  < 0.0001，Z  = 5.66, I ²  = 83.85, SMD = − 0.75, 95% CI = − 1.01, − 0.49) 和疲劳指数 ( p  = 0.02, Z  = 2.41, I ² = 2.49, SMD = − 0.39, 95% CI = − 0.72, − 0.07) 在晚上较高，而血乳酸水平在早晨较高 ( p = 0.79, Z = 0.27, I  2 =  0.73 , ^SMD  = − 0.05, 95% CI = − 0.46, − 0.35)。

结论

结果表明，昼夜变化影响肌肉的峰值和平均功率输出以及疲劳指数。然而，昼夜节律对血乳酸水平没有显着影响。导致这一发现的一个主要因素是参与者培训经验的差异。对于有效的训练处方，考虑生物钟对肌肉功率输出的影响非常重要，因为无氧运动表现明显受到一天中时间的影响。