Faculty of Health and Sports Science, Juntendo University, 1-1 Hiraka-gakuendai, Inzai, Chiba, 270-1695, Japan.
Institute of Health and Sports Science & Medicine, Juntendo University, 1-1 Hiraka-gakuendai, Inzai, Chiba, 270-1695, Japan.
Eur J Appl Physiol. 2024 Nov;124(11):3317-3323. doi: 10.1007/s00421-024-05536-w. Epub 2024 Jun 21.
Most athletes experience short-term training cessation because of illness, injury, post-season vacation, or other reasons. Passive muscle stiffness is a potential risk factor for a sprint-type hamstring strain injury, but limited information is available about the effect of short-term training cessation on passive muscle stiffness. The present study aimed to identify whether and how passive muscle stiffness of the biceps femoris long head (BFlh) would vary due to 2 weeks of training cessation in sprinters.
Passive BFlh shear-wave speed (a proxy for stiffness) was measured using ultrasound shear-wave elastography in 28 male sprinters, before and after 2 weeks of intervention. During the 2 weeks, the participants in the training-cessation group (n = 14) were allowed to maintain their normal daily activities but not to perform any physical training, including stretching and resistance exercises. The participants in the training continuation group (n = 14) performed the training (including maximum speed sprint, plyometric, and weight training) prescribed by their coaches 5 days per week.
In the training-cessation group, passive BFlh shear-wave speed increased after the 2 weeks of training cessation (4.75 ± 0.77 to 5.00 ± 0.88 m/s, P < 0.001). In contrast, there was no significant difference before and after the 2 weeks of training continuation (4.90 ± 0.85 to 4.93 ± 0.85 m/s, P = 0.521).
The present findings indicate that muscles stiffen by training cessation in sprinting athletes.
大多数运动员因疾病、受伤、赛后假期或其他原因经历短期训练停止。被动肌肉僵硬是短跑型腘绳肌拉伤的潜在危险因素，但关于短期训练停止对被动肌肉僵硬的影响的信息有限。本研究旨在确定短跑运动员因 2 周的训练停止，其股二头肌长头（BFlh）的被动肌肉僵硬是否会发生变化以及如何变化。
在 2 周的干预前后，使用超声剪切波弹性成像测量 28 名男性短跑运动员的被动 BFlh 剪切波速度（僵硬的替代指标）。在 2 周期间，训练停止组（n=14）的参与者被允许保持正常的日常活动，但不得进行任何体育训练，包括伸展和阻力运动。训练继续组（n=14）的参与者按照教练的规定每周进行 5 天的训练（包括最大速度冲刺、增强式和力量训练）。
在训练停止组中，经过 2 周的训练停止后，被动 BFlh 剪切波速度增加（4.75±0.77 至 5.00±0.88 m/s，P<0.001）。相比之下，在训练继续组中，2 周的训练前后没有显著差异（4.90±0.85 至 4.93±0.85 m/s，P=0.521）。
本研究结果表明，短跑运动员的肌肉在停止训练时会变硬。
