Reid W D, Shanks J, Samrai B
School of Rehabilitation Sciences, University of British Columbia, Vancouver, Canada.
Phys Ther. 1997 Feb;77(2):178-86. doi: 10.1093/ptj/77.2.178.
The purpose of this study was to determine the effect of a swimming endurance training program on changes in percentages and sizes of fiber types in different regions of the hamster diaphragm.
Adult male golden Syrian hamsters were randomly assigned to a control group (n = 9) or a swimming group (n = 10). Hamsters in the swimming group swam for 80 minutes per session, 5 days per week, for 13 weeks. Fiber-type percentages and sizes were determined for the costal region and for the abdominal and thoracic surfaces of the crural region of the diaphragm from cross sections processed for myofibrillar adenosine triphosphatase.
Muscle fibers in the thoracic surface of the crural region were smaller in the swimming group than in the control group. Fiber-type percentages in the diaphragm, however, were not different between groups.
Swim training may have improved the endurance of the thoracic/crural region by decreasing cross-sectional area and thus decreasing the distance for oxygen to diffuse to the internal regions of the muscle fibers.
本研究旨在确定游泳耐力训练计划对仓鼠膈肌不同区域肌纤维类型百分比及大小变化的影响。
成年雄性金黄叙利亚仓鼠被随机分为对照组（n = 9）或游泳组（n = 10）。游泳组的仓鼠每周游泳5天，每次80分钟，共持续13周。通过用于肌原纤维三磷酸腺苷酶处理的横截面，测定膈肌肋区以及膈脚区腹部和胸部表面的肌纤维类型百分比及大小。
游泳组膈脚区胸部表面的肌纤维比对照组小。然而，两组之间膈肌的肌纤维类型百分比并无差异。
游泳训练可能通过减小横截面积，从而缩短氧气扩散至肌纤维内部区域的距离，提高了膈胸/膈脚区的耐力。
