Oliveira João, Casanova Nuno, Gomes João S, Pezarat-Correia Pedro, Freitas Sandro, Vaz João R
Neuromuscular Research Lab, Faculty of Human Kinetics, University of Lisbon, Lisbon, Portugal.
School of Food Science and Nutrition, Faculty of Environment, University of Leeds, Leeds, UK.
Sports Biomech. 2024 Dec;23(12):2873-2885. doi: 10.1080/14763141.2022.2067588. Epub 2022 Apr 29.
Torque outputs exhibit non-random fluctuations in their temporal structure, i.e., complexity. Fatigue has been shown to alter this structure. The torque outputs typically become more regular, resulting in decreased adaptability. Importantly, torque complexity was shown a different recovery pattern after fatigue compared to maximal torque. However, it remains to be understood if these uncoupled patterns of recovery are muscle dependent. In addition, it also remains to be investigated if changes in maximal torque and complexity are correlated. This study investigated (i) the effects of a fatiguing protocol on the complexity and maximal torque from plantar flexors and (ii) the relationship between changes in these two outputs. Ten participants visited the laboratory, and measures were taken at baseline, immediately after, 1 h after and 24 h after the fatiguing protocol. Maximum voluntary contraction, isometric contractions at 30% of maximum and pain pressure threshold were collected. Both legs were assessed, but only one was given the fatiguing protocol. Two-way ANOVAs and correlations were conducted. The fatiguing protocol decreased torque complexity (35%) and maximal torque (20%), and they exhibited uncoupled patterns of recovery. Moreover, the correlation analysis showed no correlation between changes in these parameters. These findings support that these parameters are independent of each other.
扭矩输出在其时间结构上呈现出非随机波动，即复杂性。研究表明疲劳会改变这种结构。扭矩输出通常会变得更加规律，导致适应性下降。重要的是，与最大扭矩相比，疲劳后扭矩复杂性呈现出不同的恢复模式。然而，这些不相关的恢复模式是否依赖于肌肉仍有待了解。此外，最大扭矩和复杂性的变化是否相关也有待研究。本研究调查了：（i）疲劳方案对跖屈肌复杂性和最大扭矩的影响；（ii）这两种输出变化之间的关系。十名参与者来到实验室，在疲劳方案实施前、实施后即刻、实施后1小时和实施后24小时进行测量。收集最大自主收缩、最大收缩力30%时的等长收缩以及疼痛压力阈值。对双腿进行评估，但只有一条腿接受疲劳方案。进行了双向方差分析和相关性分析。疲劳方案降低了扭矩复杂性（约35%）和最大扭矩（约20%），并且它们呈现出不相关的恢复模式。此外，相关性分析表明这些参数的变化之间没有相关性。这些发现支持这些参数相互独立。
