Thorstensson A, Karlsson J
Acta Physiol Scand. 1976 Nov;98(3):318-22. doi: 10.1111/j.1748-1716.1976.tb10316.x.
The fatiguability of the quadriceps muscle was investigated in 10 male subjects (25-40 yrs), with inter-individual differences in fibre composition of their vastus lateralis muscles (range 25-65% fast twitch, FT, muscle fibres). Fatiguability was assessed as the decline in maximal force (in % of initial values) with 50 repeated isokinetic knee-extensions at fast angular velocity (3.14 rad/s). Each contraction lasted 0.5 s and the rest periods were about 0.7 s. Every subject was tested on two occasions and the standard deviation for a single determination of fatiguability was 1.4%. The decline in force after 50 contractions was on the average about 45%. The individual values varied, however, and a linear correlation was present between fatiguability and % FT fibres (r = 0.86, p less than 0.01). It was concluded that development of fatigue in human skeletal muscle performing repeated fast dynamic contractions with maximal effort was most marked in muscles with a high proportion FT fibres. This finding was in conformity with earlier results from animal skeletal muscle preparations.
对10名男性受试者（25 - 40岁）的股四头肌疲劳性进行了研究，这些受试者股外侧肌的纤维组成存在个体差异（快肌纤维比例范围为25% - 65%）。通过在快速角速度（3.14弧度/秒）下进行50次重复等速膝关节伸展时最大力量的下降（以初始值的百分比表示）来评估疲劳性。每次收缩持续0.5秒，休息时间约为0.7秒。每个受试者都进行了两次测试，单次疲劳性测定的标准差为1.4%。50次收缩后力量的下降平均约为45%。然而，个体值有所不同，疲劳性与快肌纤维百分比之间存在线性相关性（r = 0.86，p < 0.01）。得出的结论是，人类骨骼肌在最大努力进行重复快速动态收缩时，疲劳的发展在快肌纤维比例高的肌肉中最为明显。这一发现与早期动物骨骼肌制备的结果一致。
