很少有与时间试验相关的功能指标显示昼夜变化。用于评估昼夜效应的时间试验性能的测试/方案的多样性以及缺乏标准化方法阻碍了文献中的共识。因此,本研究的目的是调查和系统地审查与时间试验措施中的时间差异相关的证据,并研究与研究设计相关的主要方面,这些方面对于时间生物学性质的研究很重要.Manipal高等教育学院电子图书馆和卡塔尔国家图书馆的全部内容,和电子数据库:PubMed(MEDLINE),搜索了Scopus和WebofScience。发表在同行评审期刊和非同行评审研究上的研究研究,在2021年11月之前年龄≥18岁的男性成年参与者中进行筛查/纳入。在白天至少2个时间点(早上[06:30-10:30小时]与晚上[14:30-20:00小时])之间评估与任何形式的时间试验相关的测试的研究被认为是合格的。建议评估的分级,发展,和评估(GRADE)过程用于评估证据以提供建议。初步搜索显示,40篇文章中的10篇文章被认为是合格的,随后被纳入。六个是使用自行车进行的,两个使用跑步和两个使用游泳作为运动方式。在自行车和跑步计时赛中,距离范围为1至16.1公里,或15至20分钟,在游泳计时赛中50到200米。只有四项研究发现他们的一个或几个性能变量显示每日变化,晚上的值明显更好;而6项研究发现,在任何评估变量中,当日时间均无显著性意义。完成自行车计时赛的性能时间差异的幅度从2.9%到7.1%不等,而跑步和游泳在表现时间上没有发现任何差异。在骑自行车的16.1公里计时赛中,功率输出也发现晚上的表现要好得多10%。唯一观察到的其他差异是游泳时间试验期间的中风率和中风长度以及中风率(周期。min-1)在循环计时赛中。差异的大小取决于运动方式,个体时间型,个体的训练状态和样本量的差异。大多数研究中缺乏昼夜变化可以部分解释为一些方法学上的局限性和与质量和控制相关的问题。至关重要的是,评估表现的昼夜变化的研究在核心体温最小值(〜05:00h;早晨)和最大值(〜17:00h;晚上)周围使用适当的会话时间。虽然,动机/唤醒的差异,习惯性训练时间,时间型和基因型可以解释为什么一些研究/变量没有显示出一天中的时间变化,需要更多的工作来提供准确的结论。有明确的要求,未来调查将采用的标准化方法,这些方法控制与每日时间调查具体相关的因素,例如适当的熟悉程度,平衡测试管理的顺序,在受控环境中的会话和测试之间提供足够的恢复时间。
Few functional measures related to time-
trial display diurnal variation. The diversity of tests/protocols used to assess time-
trial performance on diurnal effects and the lack of a standardised approach hinder agreement in the literature. Therefore, the aims of the present
study were to investigate and systematically review the evidence relating to time-of-day differences in time-
trial measures and to examine the main aspects related to research design important for studies of a chronobiological nature. The entire content of Manipal Academy of Higher Education electronic library and Qatar National Library, and electronic databases: PubMed (MEDLINE), Scopus and Web of Science were searched. Research studies published in peer-reviewed journals and non-peer reviewed studies, conducted in male adult participants aged ≥18 y before November 2021 were screened/included. Studies assessing tests related to time-trials in any modality between a minimum of 2 time-points during the day (morning [06:30-10:30 h] vs evening [14:30-20:00 h]) were deemed eligible. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence to inform recommendations. The primary search revealed that a total of 10 from 40 articles were considered eligible and subsequently included. Six were conducted using cycling, two using running and two using swimming as the mode of exercise. Distances ranged from 1 to 16.1-km in distance or 15 to 20-min time in the cycling and running time-trials, and 50 to 200-m in the swimming time-trials. Only four studies found one or several of their performance variables to display daily variations, with significantly better values in the evening; while six studies found no time-of-day significance in any variables assessed. The magnitude of difference ranged from 2.9% to 7.1% for performance time to complete a cycling time-trial, while running and swimming did not find any differences for performance time. Power output during a 16.1-km time trial in cycling also found evening performance to be significantly better by 10%. The only other observed differences were stroke rate and stroke length during a swimming time-trial and stroke rate (cycles.min-1) during a cycling time-
trial. The magnitude of difference is dependent on exercise modality, individual chronotype, the training status of the individual and sample size differences. The lack of diurnal variation present in the majority of studies can in-part be explained with some of the methodological limitations and issues present related to quality and control. It is paramount that research assessing diurnal variation in performance uses appropriate session timings around the core body temperature minimum (~05:00 h; morning) and maximum (~17:00 h; evening). Although, differences in motivation/arousal, habitual training times, chronotypes and genotypes could provide an explanation as to why some studies/variables did not display time-of-day variation, more work is needed to provide an accurate conclusion. There is a clear demand for a rigorous, standardised approach to be adopted by future investigations which control factors that specifically relate to investigations of time-of-day, such as appropriate familiarisation, counterbalancing the order of administration of tests, providing sufficient recovery time between sessions and testing within a controlled environment.