Hatfield Disa L, Nicoll Justin X, Kraemer William J
1Department of Kinesiology, University of Rhode Island, South Kingston, Rhode Island; and 2Departments of Human Sciences, The Ohio State University, Columbus, Ohio.
J Strength Cond Res. 2016 Mar;30(3):725-32. doi: 10.1519/JSC.0000000000001207.
Circadian rhythms (CRs) persist in many physiological systems related to performance. The effects of circadian patterns on dynamic muscular power are minimal and conflicting. Furthermore, no study to date has investigated the effect of CR on bench press throws (BPTs) despite its popularity as a modality to increase muscular power. The purpose of this study was to examine the effects of circadian variations on muscular power output and hormonal changes in men. College aged men (n = 7, age: 23.6 ± 1.3 years, height: 179.9 ± 5.4 cm, and body mass: 81.5 ± 19.7 kg.) were recruited for this repeated measures study. Testing occurred at 4 different times of day (04:00, 10:00, 16:00, and 22:00 hours). Testosterone (T) and cortisol (C) hand dynamometer strength (GS), heart rate (HR), mental readiness (MR), BPT and squat jumps (SJs), power (P), and force (F) were measured at each time point. Statistical significance was set at (p ≤ 0.05). There were no significant differences in HR, MR, and GS among all time points. There were no decrements in P or F in BPT or SJ among any time point (p ≥ 0.05). Testosterone and C decreased significantly throughout the day (p ≤ 0.05). Although P and F output differed at various percentages of 1 repetition maximum, they were not affected by circadian pattern, such that muscular performance was not impaired at any time point. Practical implications of these data indicate that high force and power exercises using BPT or SJ may be performed any time of day without detrimental decreases in acute performance.
昼夜节律（CRs）在许多与运动表现相关的生理系统中持续存在。昼夜模式对动态肌肉力量的影响微乎其微且相互矛盾。此外，尽管卧推投掷（BPTs）作为一种增加肌肉力量的方式很受欢迎，但迄今为止尚无研究调查昼夜节律对其的影响。本研究的目的是检验昼夜变化对男性肌肉力量输出和激素变化的影响。招募了大学年龄男性（n = 7，年龄：23.6±1.3岁，身高：179.9±5.4厘米，体重：81.5±19.7千克）进行这项重复测量研究。测试在一天中的4个不同时间（04:00、10:00、16:00和22:00）进行。在每个时间点测量睾酮（T）、皮质醇（C）、握力（GS）、心率（HR）、心理准备状态（MR）、卧推投掷（BPT）和深蹲跳（SJs）、功率（P）和力量（F）。统计学显著性设定为（p≤0.05）。所有时间点之间的心率、心理准备状态和握力均无显著差异。任何时间点的卧推投掷或深蹲跳中的功率或力量均无下降（p≥0.05）。睾酮和皮质醇在一天中显著下降（p≤0.05）。尽管在1次重复最大值的不同百分比下功率和力量输出有所不同，但它们不受昼夜模式的影响，因此在任何时间点肌肉表现均未受损。这些数据的实际意义表明，使用卧推投掷或深蹲跳进行的高强度力量和功率练习可在一天中的任何时间进行，而不会导致急性运动表现出现有害下降。
