GEPESINE-Group of Study and Research in Neuromuscular System and Exercise, CEFE-State University of Londrina (UEL), Brazil.
J Strength Cond Res. 2011 Sep;25(9):2537-43. doi: 10.1519/JSC.0b013e318202e6a0.
This study compared the activation pattern and the fatigue rate among the superficial muscles of the quadriceps femoris (QF) during severe cycling exercise. Peak oxygen consumption (VO(2)peak) and maximal accumulated oxygen Deficit (MAOD) were established by 10 well-trained male cyclists (27.5 ± 4.1 years, 71.0 ± 10.3 kg, 173.4 ± 6.6 cm, mean VO(2)peak 56.7 ± 4.4 ml·kg·min(-1), mean MAOD 5.7 ± 1.1 L). Muscle activity (electromyographic [EMG] signals) was obtained during the supramaximal constant workload test (MAOD) and expressed by root mean square (RMS) and median frequency (MF slope). The RMS of the QF, vastus lateralis (VL) and vastus medialis (VM) muscles were significantly higher than at the beginning after 75% of exercise duration, whereas for the rectus femoris (RF), this was observed after 50% of exercise duration (p ≤ 0.05). The slope of the MF was significantly higher in the RF, followed by the VL and VM (-3.13 ± 0.52 vs. -2.61 ± 0.62 vs. -1.81 ±0.56, respectively; p < 0.05). We conclude that RF may play an important role in limiting performance during severe cycling exercise.
本研究比较了严重踏车运动时股四头肌（QF）表浅肌肉的激活模式和疲劳率。10 名训练有素的男性自行车运动员（27.5 ± 4.1 岁，71.0 ± 10.3 kg，173.4 ± 6.6 cm，平均峰值摄氧量（VO 2 peak ） 56.7 ± 4.4 ml·kg·min -1 ，平均最大累积氧亏（MAOD）5.7 ± 1.1 L）确定了最大摄氧量（VO 2 peak ）和最大累积氧亏（MAOD）。在最大恒定负荷测试（MAOD）期间获得肌肉活动（肌电图[EMG]信号），并用均方根（RMS）和中值频率（MF 斜率）表示。在运动持续时间的 75%之后，QF、股外侧肌（VL）和股中间肌（VM）的 RMS 显著高于运动开始时，而股直肌（RF）在运动持续时间的 50%后才观察到这一点（p ≤ 0.05）。MF 斜率在 RF 中显著更高，其次是 VL 和 VM（-3.13 ± 0.52 vs. -2.61 ± 0.62 vs. -1.81 ±0.56，分别;p <0.05）。我们得出结论，RF 可能在严重踏车运动中限制性能发挥重要作用。
