举重训练对男子肌比力、肌纤维的影响

安排9名有一定训练的青少年运动员参加10周举重训练。每周6次,每次8小时。训练前后用电子计算机—X线断层扫描技术(CT)测量大腿肌肉横断面积,股外肌针刺活检取样测定Ⅰ、Ⅱ型肌纤维％和面积。测定大腿伸膝肌最大随意等长力量。将结果(实验前、后)与对照组(13名无训练者)和优秀举重运动员(健将3人、一级4人)进行比较。结果表明,有训练人(实验前、后和优秀)与没有训练人(对照)在肌比力上存有差别。短、长期举重训练后,肌比力与Ⅱ型肌纤维％呈正相关。短、长期举重训练不曾改变肌纤维类型分布。举重训练对Ⅱ型肌纤维有选择性作用,且这个作用不受年龄的影响。结果还提示,肌比力的变化及肌比力与肌纤维之间的关系都会受运动项目专项特点的影响。

EFFECT OF WEIGHTLIFING ON STRENGTH PER UNIT CROSS-SECTIONAL AREA OF THE MUSCLE, MUSCLE FIBER IN MAN

29 males were involved in the study to investigate the effect of short and long term weightlifting training on the strength per unit cross-sectional area, muscle fiber and the relationship between the both. 9 young players who had some training background were arraned in a weightlifting trainging program six times a wk for 10 wk.The muscle cross-sectional area of the thigh were measured with computed tomography scanning, muscle biopsies were taken from vastus lateralis to distinguish percentage and average area of muscle fiber type I and I ,and maximal voluntary isometric torque of knee extension were measured before and after the training. The results were compared with that of control group ( 13 nonathletes ) and elite athletes group < 7 national weightlifting players ).It was found the strength per unit cross-sectional area of the muscle in the trained groups ( before, after and elite ) was higher significantly than that of the controls. That is to say, there is a difference in the strength per unit cross-sectional area of the muscle between nonathletes and trained players. After shorthand long term weightlifting training, direct correlation appeared between the strength per unit cross-sectional area of the muscle and type 11%, muscle fiber distribution had not been changed with short and long term weightlifting training.The high load weightlifting training hadselective effects on type I regardless of age. It is concluded that the speciality of the training program has influenceon the strength per unit cross-sectional area of the muscle, muscle fiber and the relationship between the strength per unit cross-sectional area of the muscle and muscle fiber type.