我们已经研究了膝关节伸肌和屈肌的等速和等距强度的昼夜节律变化的幅度,以及使用MuscleLab力速度传感器的后蹲和卧推性能。十名抵抗训练的男性(平均±SD:年龄21.5±1.1岁;体重78.3±5.2kg;身高1.71±0.07m)进行了a)在每个测力计上进行了三到四次熟悉训练,b)在一天中的不同时间进行了四次训练(03:00、09:00、15:00和21:00h)。每个会话都以平衡的顺序进行,并包括一个感知情绪状态(POMS)发作的时期,然后直肠和肌肉温度(Trec,Tm)是在休息时测量的,之后,在自行车测功机上进行5分钟标准化的150W预热。一旦完成,等速运动(60和240°·s-1用于伸展和弯曲)和具有峰值扭矩(PT)的等速测力,测量峰值扭矩时间(tPT)和峰值力(PF)以及激活%。最后,在卧床(在30、50和70kg下)和后蹲(在40、60和80kg下)锻炼之前测量Trec和Tm。一个线性编码器连接到一个用于练习和平均力(AF)的奥林匹克酒吧,测量峰值速度(PV)和达到峰值速度的时间(tPV)(MuscleLab软件;MuscleLab技术,Langesund,挪威)在运动的同心阶段。在每组之间允许五分钟的恢复,完成三次重复。使用具有重复测量和余弦分析的一般线性模型来分析数据。休息时的Trec和Tm值在晚上比早晨值高(顶相Φ:16:35和17:03h,振幅A:0.30和0.23°C,MesorM:36.64和37.43°C,p<0.05)。充满活力,快乐和疲劳情绪状态反应分别为Φ16:11和16:03h和02:05h。昼夜节律对于所有变量都是明显的,无论在AF,PF和PT值在16:18和18:34小时之间达到峰值;PV,tPV和tPT在05:54和08:03h之间达到峰值(p<0.05)。总之,力输出的昼夜节律(力,扭矩,电源,和速度)显示为等速,等距测力计和复杂的多关节运动(使用线性编码器);与晚上相比,tPV和tPT发生在早上。昼夜节律的强度可以通过便携式设备来检测,低成本仪器,具有与已建立的测力计相似的余弦特性。因此,肌肉力量可以以更直接地转移到运动和运动表现世界的方式来测量。
We have investigated the magnitude of circadian variation in Isokinetic and Isometric strength of the knee extensors and flexors, as well as back squat and bench press performance using the MuscleLab force velocity transducer. Ten resistance-trained males (mean±SD: age 21.5 ± 1.1 years; body mass 78.3 ± 5.2 kg; height 1.71 ± 0.07 m) underwent a) three to four familiarization sessions on each dynamometer and b) four sessions at different times of day (03:00, 09:00, 15:00 and 21:00 h). Each session was administered in a counterbalanced order and included a period when Perceived onset of mood states (POMS), then rectal and muscle temperature (Trec, Tm) was measured at rest, after which a 5-min standardized 150 W warm-up was performed on a cycle ergometer. Once completed, Isokinetic (60 and 240°·s-1 for extension and flexion) and Isometric dynamometry with peak torque (PT), time-to-peak-torque (tPT) and peak force (PF) and % activation was measured. Lastly, Trec and Tm were measured before the bench press (at 30, 50 and 70 kg) and back squat (at 40, 60 and 80 kg) exercises. A linear encoder was attached to an Olympic bar used for the exercises and average force (AF), peak velocity (PV) and time-to-peak-velocity (tPV) were measured (MuscleLab software; MuscleLab Technology, Langesund, Norway) during the concentric phase of the movements. Five-min recovery was allowed between each set with three repetitions being completed. General linear models with repeated measures and cosinor analysis were used to analyse the data. Values for Trec and Tm at rest were higher in the evening compared to morning values (Acrophase Φ: 16:35 and 17:03 h, Amplitude A: 0.30 and 0.23°C, Mesor M: 36.64 and 37.43°C, p < 0.05). Vigor, happy and fatigue mood states responses showed Φ 16:11 and 16:03 h and 02:05 h respectively. Circadian rhythms were apparent for all variables irrespective of equipment used where AF, PF and PT values peaked between 16:18 and 18:34 h; PV, tPV and tPT peaked between 05:54 and 08:03 h (p < 0.05). In summary, circadian rhythms in force output (force, torque, power, and velocity) were shown for isokinetic, isometric dynamometers and complex multi-joint movements (using a linear encoder); where tPV and tPT occur in the morning compared to the evening. Circadian rhythms in strength can be detected using a portable, low-cost instrument that shows similar cosinor characteristics as established dynamometers. Hence, muscle-strength can be measured in a manner that is more directly transferable to the world of athletic and sports performance.