Bieuzen F, Hausswirth C, Couturier A, Brisswalter J
Department of Ergonomics, University of Toulon Var, avenue de l'Université, La Garde Cedex, Toulon, France.
Int J Sports Med. 2008 May;29(5):401-7. doi: 10.1055/s-2007-965568. Epub 2007 Sep 18.
The aim of this study was to investigate the effect of concentric or eccentric fatiguing exercise on cycling pattern. Eleven well trained cyclists completed three sessions of cycling (control cycling test [CTRL], cycling following concentric [CC] or eccentric [ECC] knee contractions) at a mean power of 276.8 +/- 26.6 Watts. Concentric and eccentric knee contractions were performed at a load corresponding to 80 % of one repetition maximum with both legs. Before and after CTRL, CC or ECC knee contractions and after cycling, a maximal voluntary contraction (MVC) test was performed. Cardiorespiratory, mechanical and electromyographic activity (EMG) of the rectus femoris, vastus lateralis and biceps femoris muscles were recorded during cycling. A significant decrease in MVC values was observed after CC and ECC exercises and after the cycling. ECC exercise induced a significant decrease in EMG root mean square during MVC and a decrease in pedal rate during cycling. EMG values of the three muscles were significantly higher during cycling exercise following CC exercise when compared to CTRL. The main finding of this study was that a prior ECC exercise induces a greater neuromuscular fatigue than a CC exercise, and changes in cycling pattern.
本研究的目的是调查向心或离心疲劳运动对骑行模式的影响。11名训练有素的自行车运动员以平均功率276.8±26.6瓦完成了三轮骑行（对照骑行测试[CTRL]、向心收缩[CC]或离心收缩[ECC]后的骑行）。双腿均以相当于一次最大重复量80%的负荷进行向心和离心膝关节收缩。在CTRL、CC或ECC膝关节收缩之前和之后以及骑行之后，进行了最大自主收缩（MVC）测试。在骑行过程中记录股直肌、股外侧肌和股二头肌的心肺、机械和肌电图活动（EMG）。在CC和ECC运动后以及骑行后，观察到MVC值显著下降。ECC运动导致MVC期间EMG均方根显著下降，骑行期间踏板率下降。与CTRL相比，CC运动后的骑行运动期间，三块肌肉的EMG值显著更高。本研究的主要发现是，先前的ECC运动比CC运动引起更大的神经肌肉疲劳，并改变骑行模式。
