【摘要】 目的：探讨体力疲劳（physical fatigue,PF）、脑力疲劳（mental fatigue,MF）及体脑混合疲劳（physical and mental mixed fatigue,PMF）对橄榄球运动员下肢爆发力和心率变异性（heart rate variability,HRV）的影响。方法：选取15名橄榄球运动员作为研究对象。采用随机交叉对照试验设计，受试者需完成PF、MF、PMF干预任务，并在每次实验后进行下肢爆发力和HRV测试。采用单因素重复测量方差分析进行统计学分析。结果：1)在跳深跳跃腾空高度指标上，PMF相较于MF显示出了更低的腾空高度（P<0.05）。2)在下蹲跳的垂直地面反作用力峰值(peak vertical ground reaction force,vGRF_peak)指标上，PF和PMF相较于基线和MF均显示出了更小的vGRF_peak（P<0.05）；在跳深的vGRF_peak指标上，PMF相较于基线和MF显示出了更小的v GRFpeak（P<0.05）。3)不同疲劳方案对下蹲跳的力量发展速率具有显著差异（P<0.05），相较于基线、PF和MF,PMF显示出了更小的力量发展速率（P<0.05）。4)不同疲劳方案对跳深平均功率输出、反应力量指数和反应力量比具有显著影响（P<0.05），在平均功率输出指标上，相较于基线，PF、MF和PMF均显示出了更低的平均功率输出（P<0.05）；在反应力量指数指标上，相较于基线，MF和PMF显示出了更低的反应力量指数（P<0.05）；在反应力量比指标上，相较于基线，MF和PMF显示出了更低的反应力量比（P<0.05）；相较于PF,MF显示出了更低的反应力量比（P<0.05）。5)不同疲劳方案对HRV的正常心跳间期的标准差（standard deviation of the normal to normal intervals,SDNN）、相邻R-R间期差值的均方根（root mean square successive difference,RMSSD）、高频（high frequency,HF）和低频（low frequency,LF）指标均有显著差异（P<0.05），相较于基线和MF,PF和PMF均显示出了更小的SDNN、RMSSD、HF和LF（P<0.05）。结论：PF、MF和PMF均对橄榄球运动员的下肢爆发力产生了显著影响。其中，相较于PF和MF,PMF对vGRF_peak以及反应性力量方面均产生了显著影响，表明PMF可能通过多重机制影响运动员的运动表现，且其影响可能大于单一类型的疲劳。此外，在HRV方面，PF和PMF均能降低HRV相关指标，但PMF与PF之间，以及基线与MF之间并未观察到显著差异。表明PMF对心脏应激反应和自主神经系统调节能力的即时影响与PF相似，而MF未表现出显著影响。更多还原

【Abstract】 Objective: To investigates the effects of physical fatigue（PF）, mental fatigue（MF）,and physical-mental mixed fatigue（PMF） on the lower limb explosive power and heart rate variability（HRV） of American football players. Methods: Fifteen American football players were selected as research subbjects to participated in the experimental design of a randomized crossover controlled trial. The subjects were required to completed intervention tasks for PF, MF, and PMF, followed by tests for lower limb explosive power and HRV after each experiment. Oneway repeated measures analysis of variance was used for statistical analysis. Results: 1) In the drop jump（DJ）, PMF significantly reduced jump height compared to MF（P<0.05）. 2) For the counter movement jump（CMJ）, PF and PMF showed significantly lower peak vertical ground reaction force(vGRF_peak) than baseline and MF（P<0.05）; DJ also revealed a significantly lower vGRF_peak for PMF（P<0.05）. 3) The rate of force development（RFD） in CMJ was significantly affected by different fatigue protocols（P<0.05）, with PMF all reducing RFD compared to baseline, PF, and MF（P<0.05）. 4) Different fatigue protocols significantly influenced average power output, reactive strength index（RSI）, and reactive strength ratio（RSR） in DJ（P<0.05）. PF, MF, and PMF all lowered average power output compared to baseline（P<0.05）; RSI and RSR were reduced in MF and PMF（P<0.05）, with MF showing a lower RSR than PF（P<0.05）. 5) Different fatigue protocols significantly affected HRV indices: standard deviation of the normal to normal intervals（SDNN）, root mean square successive difference（RMSSD）, high frequency（HF）, and low frequency（LF）（P<0.05）. PF and PMF both decreased SDNN,RMSSD, HF, and LF compared to baseline and MF（P<0.05）. Conclusions: PF, MF, and PMF have significant effects on the lower limb explosive power of American football players.Among them, compared with PF and MF, PMF has a more pronounced effect on vGRF_peak and reactive strength, indicating that PMF may influence athletic performance through multiple mechanisms, potentially more than individual fatigue types. In terms of HRV, both PF and PMF decrease HRV-related indicators, with no significant differences between PMF and PF, or between baseline and MF, indicating that PMF’s immediate effects on cardiac stress response and autonomic nervous system regulation are similar to PF, while MF shows no significant effect.更多还原