Chilibeck P D, Syrotuik D G, Bell G J
Faculty of Physical Education and Recreation, University of Alberta, Edmonton Alberta, Canada.
Int J Sports Med. 2002 Jan;23(1):33-9. doi: 10.1055/s-2002-19269.
We examined the effect of combined strength and endurance training on quantitative estimates of mitochondria in subsarcolemmal and intermyofibrillar regions of muscle fibers. Ten subjects (five males, five females) participated in a 12 week program of combined strength and endurance training. Seven subjects (three males and four females) served as controls. Biopsy samples from the vastus lateralis were obtained before and after training in both groups and also at the mid-point of training in the exercise group. Measurement of succinate dehydrogenase activity throughout muscle fibers, as a quantitative estimate of mitochondrial subpopulations, revealed no differences between exercise and control groups before and after training. Within the exercise group, there was a significant increase in succinate dehydrogenase activity in all regions of muscle fibers from before to after training. There was also a significant increase in succinate dehydrogenase activity in the subsarcolemmal, relative to the intermyofibrillar region from mid-(six weeks) to after-training ( regional distribution x time; p < 0.05). This may have been associated with an oxidative shift in fiber types, as type I fiber percentage was increased in the exercise, compared to the control group (group x time; p < 0.05). We conclude that mitochondrial populations undergo differential changes throughout training. IMF mitochondria increase in a linear manner throughout training, while SS mitochondria undergo a preferential increase late in training. This increase late in training may be related to an increase in proportion of type I fibers.
我们研究了力量与耐力联合训练对肌纤维肌膜下和肌原纤维间区域线粒体定量评估的影响。10名受试者（5名男性，5名女性）参与了一项为期12周的力量与耐力联合训练计划。7名受试者（3名男性和4名女性）作为对照组。两组均在训练前后以及运动组训练中期采集股外侧肌活检样本。通过测量整个肌纤维中的琥珀酸脱氢酶活性，作为线粒体亚群的定量评估，结果显示训练前后运动组与对照组之间无差异。在运动组内，训练前后肌纤维所有区域的琥珀酸脱氢酶活性均显著增加。从训练中期（6周）到训练后，肌膜下区域的琥珀酸脱氢酶活性相对于肌原纤维间区域也显著增加（区域分布×时间；p<0.05）。这可能与纤维类型的氧化转变有关，因为与对照组相比，运动组中I型纤维百分比增加（组×时间；p<0.05）。我们得出结论，线粒体群体在整个训练过程中发生了不同的变化。在整个训练过程中，肌原纤维间线粒体呈线性增加，而肌膜下线粒体在训练后期优先增加。训练后期的这种增加可能与I型纤维比例的增加有关。
