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.

中文翻译：

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在高强度区域跑步期间步幅特征的机械偏差与肌肉氧合下降有关


我们通过研究典型步幅特征的机械偏差与肌肉氧饱和度（SmO 2 ）在股四头肌中。 16名青少年竞技跑者在室外跑道上进行了8分钟的力竭跑步测试。使用惯性测量装置连续监测运行力学。股直肌SmO 2通过近红外光谱连续监测总血红蛋白（血容量的测量）。采用一类支持向量机 (OCSVM) 建模对运动学数据进行特定主题分析。统计分析包括主成分分析、方差分析和相关分析。随着跑步测试的进行，与典型步幅特征的机械偏差增加。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）。氧化钐2从基线时的 74.3 ± 8.4% 下降到结束时的 10.1 ± 6.8% ( p < 0.001）。中度负相关（ r =−0.61， p = 0.013) 发现平均 SmO 2以及最后 15% 的跑步过程中异常步幅的百分比。在高强度跑步期间，跑步生物力学可能会发生变化，这与股四头肌氧合减少有关。这些参数凸显了在训练中使用跑步运动学和肌肉氧合来优化表现并降低受伤风险的潜力。 我们的研究有助于理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。