Venhorst Andreas, Micklewright Dominic P, Noakes Timothy D
Department of Human Biology, Division of Exercise Science and Sports Medicine, University of Cape Town, Newlands, 7725, South Africa.
School of Sport, Rehabilitation and Exercise Sciences, University of Essex, Colchester, CO4 3SQ, UK.
Sports Med Open. 2018 Jul 10;4(1):30. doi: 10.1186/s40798-018-0144-1.
"Hitting the wall" (HTW) can be understood as a psychophysiological stress process characterised by (A) discrete and poignant onset, (B) dynamic interplay between physiological, affective, motivational, cognitive, and behavioural systems, and (C) unintended alteration of pace and performance. A preceding companion article investigated the psychophysiological responses to 20-km self-paced treadmill time trials after producing exercise-induced muscle damage (EIMD) via a standardised muscle-lengthening contraction protocol.
A 5-step procedure was applied determining the extent to which the observed data fit the hypothesised cause-effect relationships. Running with EIMD negatively impacts performance fatigability via (A) amplified physiological responses and a non-adaptive distress response and (B) deterioration in perceived fatigability: increase in perceived physical strain precedes decrease in valence, which in turn precedes increase in action crisis, eventually dissolving the initially aspired performance goal.
First, haematological indicators of EIMD predicted increased blood cortisol concentration, which in turn predicted increased performance fatigability. Second, perceived physical strain explained 44% of the relationship between haematological indicators of EIMD and valence, which in turn predicted increased action crisis, which in turn predicted increased performance fatigability. The observed data fitted the hypothesised dual-pathway model well with good model-fit indices throughout.
The hypothesised interrelationships between physiological strain, perception, and heuristic and deliberative decision-making processes in self-regulated and goal-directed exercise behaviour were applied, tested, and confirmed: amplified physiological strain and non-adaptive distress response as well as strain-perception-thinking-action coupling impact performance fatigability. The findings provide novel insights into the psychophysiological processes that underpin the phenomenological experience of HTW and alteration in pacing behaviour and performance.
“撞墙期”(HTW)可被理解为一种心理生理应激过程,其特征为:(A)离散且强烈的发作;(B)生理、情感、动机、认知和行为系统之间的动态相互作用;以及(C)步速和表现的意外改变。之前的一篇相关文章通过标准化的肌肉拉长收缩方案诱导运动性肌肉损伤(EIMD)后,研究了对20公里自定步速跑步机时间测试的心理生理反应。
采用五步程序来确定观察到的数据与假设的因果关系的拟合程度。EIMD状态下跑步会通过以下方式对运动疲劳产生负面影响:(A)生理反应增强和非适应性应激反应;以及(B)疲劳感恶化:身体应变感增加先于情绪效价降低,情绪效价降低又先于行动危机增加,最终导致最初设定的表现目标瓦解。
首先,EIMD的血液学指标预测血液皮质醇浓度升高,进而预测运动疲劳增加。其次,身体应变感解释了EIMD血液学指标与情绪效价之间44%的关系,情绪效价进而预测行动危机增加,行动危机增加又预测运动疲劳增加。观察到的数据与假设的双路径模型拟合良好,整体模型拟合指标良好。
在自我调节和目标导向的运动行为中,生理应激、感知以及启发式和审慎决策过程之间的假设相互关系得到了应用、测试和证实:生理应激增强和非适应性应激反应以及应激-感知-思维-行动耦合会影响运动疲劳。这些发现为支撑HTW现象学体验以及步速行为和表现改变的心理生理过程提供了新的见解。