Abstract：
We explored the impact of running in the severe intensity domain on running mechanics and muscle oxygenation in competitive runners by investigating the relationship between mechanical deviations from typical stride characteristics and muscle oxygen saturation (SmO2) in the quadriceps muscle. Sixteen youth competitive runners performed an 8-min exhaustive running test on an outdoor track. Running mechanics were continuously monitored using inertial measurement units. Rectus femoris SmO2 and total hemoglobin (a measure of blood volume) were continuously monitored by near-infrared spectroscopy. One-class support vector machine (OCSVM) modeling was employed for subject-specific analysis of the kinematic data. Statistical analysis included principal component analysis, ANOVA, and correlation analysis. Mechanical deviations from typical stride characteristics increased as the running test progressed. Specifically, the percentage of outliers in the OCSVM model rose gradually from 2.2 ± 0.8% at the start to 43.6 ± 28.2% at the end (p < 0.001, mean ± SD throughout). SmO2 dropped from 74.3 ± 8.4% at baseline to 10.1 ± 6.8% at the end (p < 0.001). A moderate negative correlation (r = -0.61, p = 0.013) was found between the average SmO2 and the percentage of outlier strides during the last 15% of the run. During high-intensity running, alterations in running biomechanics may occur, linked to decreased quadriceps muscle oxygenation. These parameters highlight the potential of using running kinematics and muscle oxygenation in training to optimize performance and reduce injury risks. Our research contributes to understanding biomechanical and physiological responses to endurance running and emphasizes the importance of individualized monitoring.
摘要：
我们通过研究典型步幅特征的机械偏差与股四头肌的肌氧饱和度（SmO2）之间的关系，探索了在严重强度域中跑步对竞技跑步者的跑步力学和肌肉氧合的影响。16名青年竞赛者在户外赛道上进行了8分钟的详尽跑步测试。使用惯性测量单元连续监测运行力学。通过近红外光谱法连续监测股直肌SmO2和总血红蛋白(血容量的量度)。一类支持向量机（OCSVM）建模用于运动学数据的特定主题分析。统计分析包括主成分分析，方差分析,和相关分析。随着运行测试的进行，与典型步幅特性的机械偏差会增加。具体来说,OCSVM模型中异常值的百分比从开始时的2.2±0.8％逐渐上升到结束时的43.6±28.2％（p<0.001，平均值±SD）。SmO2从基线时的74.3±8.4%下降到结束时的10.1±6.8%(p<0.001)。在运行的最后15％中，平均SmO2与异常步幅百分比之间存在中度负相关（r=-0.61，p=0.013）。在高强度跑步时，可能会发生跑步生物力学的改变，与股四头肌的氧合减少有关.这些参数突出了在训练中使用跑步运动学和肌肉氧合的潜力，以优化表现并降低受伤风险。我们的研究有助于了解耐力跑的生物力学和生理反应，并强调个性化监测的重要性。
