Anderson Austin, Murray Gillian, Herlihy Meaghan, Weiss Chloe, King Jacob, Hutchinson Ellen, Albert Neil, Ingram Krista K
Department of Biology, Colgate University, NY, US.
Department of Psychology, Colgate University, NY, US.
J Circadian Rhythms. 2018 Aug 3;16:8. doi: 10.5334/jcr.165.
Although individual athletic performance generally tends to peak in the evening, individuals who exhibit a strong diurnal preference perform better closer to their circadian peak. Time-of-day performance effects are influenced by circadian phenotype (diurnal preference and chronotype-sleep-wake patterns), homeostatic energy reserves and, potentially, genotype, yet little is known about how these factors influence physiological effort. Here, we investigate the effects of time of day, diurnal preference, chronotype, and (a circadian clock gene) genotype on both effort and performance in a population of Division I collegiate swimmers (n = 27). Participants competed in 200m time trials at 7:00 and 19:00 and were sampled pre- and post-trial for salivary α-amylase levels (as a measure of physiological effort), allowing for per-individual measures of performance and physiological effort. Hair samples were collected for genotype analysis (a variable-number tandem-repeat (VNTR) and a single nucleotide polymorphism (SNP) in ). Our results indicate significant and parallel time-of-day by circadian phenotype effects on swim performance and effort; evening-type swimmers swam on average 6% slower with 50% greater α-amylase levels in the morning than they did in the evening, and morning types required 5-7 times more effort in the evening trial to achieve the same performance result as the morning trial. In addition, our results suggest that these performance effects may be influenced by gene (circadian clock gene variants) by environment (time of day) interactions. Participants homozygous for the length variant (rs57875989) or who possess a single G-allele at SNP rs228697 swam 3-6% slower in the morning. Overall, these results suggest that intra-individual variation in athletic performance and effort with time of day is associated with circadian phenotype and genotype.
尽管个体的运动表现通常在傍晚达到峰值，但那些表现出强烈昼夜偏好的个体在更接近其昼夜峰值时表现得更好。一天中不同时间的表现受昼夜节律表型（昼夜偏好和生物钟类型 - 睡眠 - 觉醒模式）、稳态能量储备以及可能的基因型影响，但对于这些因素如何影响生理努力知之甚少。在这里，我们研究了一天中的时间、昼夜偏好、生物钟类型以及（一种生物钟基因）基因型对一组一级大学游泳运动员（n = 27）的努力程度和表现的影响。参与者在早上7:00和晚上19:00进行200米计时赛，并在赛前和赛后采集唾液α - 淀粉酶水平样本（作为生理努力程度的指标），从而能够对每个个体的表现和生理努力程度进行测量。采集头发样本进行基因型分析（该基因中的可变数目串联重复序列（VNTR）和单核苷酸多态性（SNP））。我们的结果表明，昼夜节律表型对游泳表现和努力程度存在显著且平行的一天中不同时间的影响；夜型游泳者早上的平均游泳速度比晚上慢6%，且α - 淀粉酶水平比晚上高50%，而晨型游泳者在晚上的比赛中要达到与早上比赛相同的成绩，所需的努力程度是早上的5至7倍。此外，我们的结果表明，这些表现影响可能受基因（生物钟基因变体）与环境（一天中的时间）相互作用的影响。对于该基因长度变体（rs57875989）纯合或在SNP rs228697处拥有单个G等位基因的参与者，早上的游泳速度慢3 - 6%。总体而言，这些结果表明，个体运动表现和努力程度随一天中时间的变化与昼夜节律表型和该基因的基因型有关。
