Lebesque Loïc, Scaglioni Gil, Manckoundia Patrick, Martin Alain
INSERM UMR1093-CAPS, Université de Bourgogne, UFR Des Sciences du Sport, UFR STAPS, Campus Universitaire, BP 27877, F-21000, Dijon, France.
Geriatrics Internal Medicine Department, University Hospital of Dijon Bourgogne, 21079, Dijon Cedex, France.
Eur J Appl Physiol. 2025 Apr;125(4):1115-1127. doi: 10.1007/s00421-024-05660-7. Epub 2024 Nov 25.
Neuromuscular fatigability is task-dependent, but the influence of the contraction pattern on neuromuscular fatigability is largely unknown. Therefore, the present study aims to investigate if neuromuscular fatigability is affected by the contraction pattern of exhausting isometric exercises.
Thirteen participants sustained a plantar flexors MVC for 1 min (MVC) before and after exhausting exercises designed to produce a similar mean torque (30% MVC), and following a 10-min rest period. Exercises consisted of intermittent (INT), continuous (CON) or variable (continuous contraction alternating between moderate and low intensity, VAR) contractions performed until task failure.
The INT resulted in greater exercise duration and torque-time integral than CON and VAR. MVC similarly decreased after all exercises due to neural and muscular impairments. The torque loss during the MVC increased after all exercises to a similar extent, mainly because of neural alterations. Contrary to MVC, the torque loss during the MVC returned to baseline value after the recovery period.
INT, CON and VAR exercises, performed with identical mean torque and until exhaustion, led to a similar neuromuscular fatigability. When the mean torque is matched among exercises, the contraction pattern does not influence the extent of neuromuscular fatigability, assessed through the maximal torque production and sustainability. The present findings are crucial to consider for the management of neuromuscular fatigability in physical conditioning in both athletes and patients.
神经肌肉疲劳具有任务依赖性，但收缩模式对神经肌肉疲劳的影响在很大程度上尚不清楚。因此，本研究旨在调查力竭性等长运动的收缩模式是否会影响神经肌肉疲劳。
13名参与者在进行旨在产生相似平均扭矩（30%最大自主收缩，MVC）的力竭运动之前和之后，以及在10分钟的休息期后，维持一次足底屈肌最大自主收缩1分钟（MVC）。运动包括间歇性（INT）、持续性（CON）或变量性（中等强度和低强度交替的持续性收缩，VAR）收缩，直至任务失败。
与CON和VAR相比，INT导致更长的运动持续时间和扭矩-时间积分。由于神经和肌肉损伤，所有运动后MVC均同样降低。所有运动后，MVC期间的扭矩损失均以相似程度增加，主要是由于神经改变。与MVC不同，恢复期后MVC期间的扭矩损失恢复至基线值。
以相同平均扭矩进行直至力竭的INT、CON和VAR运动，导致相似的神经肌肉疲劳。当运动之间平均扭矩匹配时，收缩模式不会影响通过最大扭矩产生和可持续性评估的神经肌肉疲劳程度。本研究结果对于运动员和患者体能训练中神经肌肉疲劳的管理具有重要参考意义。
