Lüthi J M, Howald H, Claassen H, Rösler K, Vock P, Hoppeler H
Int J Sports Med. 1986 Jun;7(3):123-7. doi: 10.1055/s-2008-1025748.
Muscle strength, muscle cross-sectional area, fiber size, fiber type distribution, capillarity, and mitochondrial volume were estimated before and after 6 weeks of heavy-resistance exercise. Isokinetic torque production of the knee extensor muscles increased by a total of 17.6%, mainly during the first half of the training period. The cross-sectional area of the vastus lateralis muscle increased by 8.4%, mainly during the second half of the training period. Morphometrically determined fiber size, fiber type distribution, and capillarity from biopsies of vastus lateralis did not change significantly with training. Likewise, the surface densities of inner and outer mitochondrial membranes as well as the volume density of myofibrils remained unchanged. In contrast, the volume density of mitochondria decreased by 9.6%. However, due to the increase in total muscle volume, the calculated absolute volume of mitochondria remained constant, whereas the absolute volume of myofibrils increased by 10%. It is concluded that strength training of short duration in previously untrained young male subjects does not change the ultrastructural composition of mitochondria and that the apparent dilution of mitochondria can quantitatively be accounted for by the increase in myofibrillar volume.
在进行6周的大阻力运动前后，对肌肉力量、肌肉横截面积、纤维大小、纤维类型分布、毛细血管密度和线粒体体积进行了评估。膝伸肌的等速扭矩产生总共增加了17.6%，主要发生在训练期的前半段。股外侧肌的横截面积增加了8.4%，主要发生在训练期的后半段。通过形态学方法确定的股外侧肌活检样本中的纤维大小、纤维类型分布和毛细血管密度并未因训练而发生显著变化。同样，线粒体内外膜的表面密度以及肌原纤维的体积密度也保持不变。相比之下，线粒体的体积密度下降了9.6%。然而，由于肌肉总体积的增加，计算得出的线粒体绝对体积保持不变，而肌原纤维的绝对体积增加了10%。得出的结论是，在之前未经训练的年轻男性受试者中进行短期力量训练不会改变线粒体的超微结构组成，并且线粒体明显的稀释可以通过肌原纤维体积的增加在数量上得到解释。
