Table 2_Effects of lower extremity neuromuscular and mechanical characteristics on running economy and sports performance of long-distance runners under different relative paces.xlsx

ObjectiveTo explore the potential correlational patterns between lower extremity explosive power, strength balance, joint stiffness, neuromuscular characteristics and running economy (RE) as well as personal best (PB) of long-distance runners under different relative paces, so as to provide a preliminary theoretical clues for optimizing endurance training.
MethodsTen male second-class long-distance runners were recruited. Under the paces of PB70%, PB80% and PB90%, RE, maximal oxygen uptake (VO2max), lower extremity explosive power (CMJ, SJ, EUR, RSI), joint peak torque ratio (PTR), joint stiffness and neuromuscular indicators (RMS, CAR) were tested using gas metabolism analysis, force platform, isokinetic strength testing system, motion capture system and electromyography equipment. Data were processed by one-way repeated measures analysis of variance, paired samples t-test and Pearson correlation analysis.
ResultsRE increased significantly with the increase of pace (p < 0.05), and the correlation between RE and PB at PB80% and PB90% was stronger than that between VO2max and PB; RSI was significantly negatively correlated with RE70%, RE90% and PB (p < 0.05), while CMJ, SJ and EUR had no significant correlation; at 180°/s angular velocity, the hip joint flexor eccentric-extensor concentric PTR was significantly positively correlated with RE70%, RE90% and PB, and the knee joint flexor concentric-extensor eccentric PTR was significantly positively correlated with RE at all paces and PB (p < 0.05); knee joint stiffness was significantly negatively correlated with RE at all paces (p < 0.05); the RMS of vastus medialis (VM) was significantly positively correlated with RE70% and RE90%, and the knee joint CAR was significantly negatively correlated with RE at all paces (p < 0.05).
ConclusionThis study is strictly exploratory and hypothesis-generating. RE is a core indicator potentially associated with long-distance running performance. RSI, specific hip and knee PTR at 180°/s angular velocity, knee joint stiffness and knee joint neuromuscular activation characteristics (VM RMS, knee joint CAR) show potential correlational associations with RE. The associations between these indicators and RE are pace-dependent and joint-specific, which can provide preliminary scientific reference for generating hypotheses about long-distance running training.

研究目的：探索不同相对配速下，长跑运动员下肢爆发力、肌力平衡、关节刚度、神经肌肉特征与跑步经济性（running economy, RE）及个人最佳成绩（personal best, PB）之间的潜在关联模式，以期为耐力训练优化提供初步理论线索。
研究方法：招募10名男子二级长跑运动员，在个人最佳成绩70%（PB70%）、80%（PB80%）及90%（PB90%）配速条件下，采用气体代谢分析系统、测力台、等速肌力测试系统、运动捕捉系统及肌电设备，测试跑步经济性、最大摄氧量（maximal oxygen uptake, VO2max）、下肢爆发力（CMJ、SJ、EUR、RSI）、关节峰力矩比（PTR）、关节刚度及神经肌肉指标（肌电均方根（root mean square, RMS）、肌电共激活率（coactivation ratio, CAR））。数据采用单因素重复测量方差分析、配对样本t检验及皮尔逊相关分析进行处理。
研究结果：跑步经济性随配速提升呈显著上升趋势（p < 0.05）；在PB80%及PB90%配速下，跑步经济性与个人最佳成绩的相关性强于最大摄氧量与个人最佳成绩的相关性。反应力量指数（RSI）与RE70%、RE90%及个人最佳成绩呈显著负相关（p < 0.05），而CMJ、SJ及EUR无显著相关性。在180°/s角速度下，髋关节屈肌离心-伸肌向心PTR与RE70%、RE90%及个人最佳成绩呈显著正相关；膝关节屈肌向心-伸肌离心PTR与各配速下的跑步经济性及个人最佳成绩均呈显著正相关（p < 0.05）。膝关节刚度与各配速下的跑步经济性呈显著负相关（p < 0.05）。股内侧肌（vastus medialis, VM）的RMS与RE70%、RE90%呈显著正相关；膝关节肌电共激活率（CAR）与各配速下的跑步经济性呈显著负相关（p < 0.05）。
研究结论：本研究属于严格的探索性及假说生成性研究。跑步经济性是与长跑运动表现潜在相关的核心指标。反应力量指数（RSI）、180°/s角速度下特定的髋及膝关节PTR、膝关节刚度及膝关节神经肌肉激活特征（VM RMS、膝关节CAR）与跑步经济性存在潜在关联。上述指标与跑步经济性的关联具有配速依赖性及关节特异性，可为长跑训练相关假说的构建提供初步科学参考。