Allemeier C A, Fry A C, Johnson P, Hikida R S, Hagerman F C, Staron R S
Department of Biological Sciences, College of Osteopathic Medicine, Ohio University, Athens 45701.
J Appl Physiol (1985). 1994 Nov;77(5):2385-90. doi: 10.1152/jappl.1994.77.5.2385.
Eleven men sprint trained two to three times per week for 6 wk to investigate possible exercise-induced slow-to-fast fiber type conversions. Six individuals served as controls. Both groups were tested at the beginning and end of the study to determine anaerobic performance and maximal oxygen consumption. In addition, pre- and postbiopsies were extracted from the vastus lateralis muscle and were analyzed for fiber type composition, cross-sectional area, and myosin heavy chain (MHC) content. No significant changes were found in anaerobic or aerobic performance variables for either group. Although a trend was found for a decrease in the percentage of type IIb fibers, high-intensity sprint cycle training caused no significant changes in the fiber type distribution or cross-sectional area. However, the training protocol did result in a significant decrease in MHC IIb with a concomitant increase in MHC IIa for the training men. These data appear to support previous investigations that have suggested exercise-induced adaptations within the fast fiber population (IIb-->IIa) after various types of training (endurance and strength).
11名男性每周进行两到三次短跑训练，持续6周，以研究运动诱导的慢肌纤维向快肌纤维类型转换的可能性。6名个体作为对照组。两组在研究开始和结束时均进行测试，以确定无氧运动能力和最大耗氧量。此外，从股外侧肌提取活检前和活检后的样本，分析纤维类型组成、横截面积和肌球蛋白重链（MHC）含量。两组的无氧或有氧运动能力变量均未发现显著变化。尽管发现IIb型纤维百分比有下降趋势，但高强度短跑周期训练并未导致纤维类型分布或横截面积发生显著变化。然而，训练方案确实导致训练组男性的MHC IIb显著下降，同时MHC IIa增加。这些数据似乎支持了之前的研究，这些研究表明在各种类型的训练（耐力和力量）后，快肌纤维群体（IIb→IIa）内会发生运动诱导的适应性变化。
