在糖有氧供能条件下不同强度训练后骨骼肌形态及超量恢复规律的变化

Changes in the skeletal muscle morphology and supercompensation after different intensities of training under aerobic energy supply

背景:超量恢复理论已有一定的发展历程,但骨骼肌在糖有氧供能运动后的"超量恢复"规律的研究则较为鲜见。目的:通过糖有氧供能条件下不同周期的游泳训练,观察并测定大鼠训练后恢复期的骨骼肌形态结构的变化,以及能源物质和代谢酶的超量恢复规律。方法:雄性SD大鼠132只按不同训练强度随机分为4组:小强度训练组(42只)、中强度训练组(42只)、大强度训练组(42只)和安静对照组(6只)。将各训练组大鼠先进行1周的适应性游泳,然后按安排进行1周的游泳训练,负重为体质量的6%,大运动量为每组3次,中运动量为每组2次,小运动量为每组1次,每次游泳时间以糖有氧系统供能为主16 min为标准。训练结束取大鼠腓肠肌内侧头进行染色切片,光镜下观察大鼠训练结束后即刻、12,24,36,48,60和72 h的骨骼肌的形态结构变化,测定腓肠肌中肌糖原、肌酸激酶、超氧化物歧化酶及血清肌酸激酶等指标,并分析糖有氧供能运动后骨骼肌微损伤变化及各指标超量恢复的规律。结果与结论:(1)小强度训练组肌糖原在运动后48 h显著高于对照组(P<0.01),组织与血清肌酸激酶的活性,显著低于对照组(P<0.05),超量恢复出现在运动后的24-48 h;(2)中强度训练组肌糖原和超氧化物歧化酶均显著高于对照组(P<0.01),组织与血清肌酸激酶活性明显低于对照组(P<0.05),超量恢复在运动后的48-60 h;(3)大强度训练组的肌糖原在60 h高于对照组(P<0.05),超氧化物歧化酶在48 h显著高于对照组(P<0.01),其他指标未出现超量恢复;(4)结果表明,糖有氧运动结束即刻,中、大强度组的训练使大鼠肌细胞结构出现微损伤,且训练强度越大骨骼肌损伤就越明显;运动后恢复期,中等强度组的骨骼肌形态结构恢复得最好,最佳的时间段在48 h。在糖有氧供能条件下,中等强度训练组的能源物质和有氧酶活性的超量恢复更明显,因此,中等强度的训练模式更适合糖有氧供能型的运动,其超量恢复时间出现在运动后的48-60 h。

BACKGROUND： Supercompensation has experienced a long evolutional process, but the supercompensation rule of skeletal muscle after glycogen aerobic energy training is little reported. OBJECTIVE： To observe the morphological changes of skeletal muscle, and supercompensation rules of energy substances and metabolic enzymes after different cycles of swimming training under glycogen aerobic energy supply in rats. METHODS： Totally 132 male Sprague-Dawley rats were randomized into four groups： group A（n=42）, one cycle of training, low intensity training once a week; group B（n=42）, two cycles of training, medium intensity training twice a week; group C：（n=42）, three cycles of training, high-intensity training three times a week; control group（n=6）. Firstly training group rats underwent 1-week adaptability swimming, and then 1-week swimming training, 16 minutes once. The rat gastrocnemius was stained to observe morphological changes of the skeletal muscle under light microscope immediately, at 12, 24, 36, 48, 60 and 72 hours after training. The contents of muscle glycogen, creatine kinase, and superoxide dismutase in the gastrocnemius and serum level of creatine kinase were assayed; and the changes in the skeletal muscle injury and supercompensation rules of each index were analyzed. RESULTS AND CONCLUSION： Compared with the control group, in the group A, the muscle glycogen at 48 hours after training was significantly increased（P〈0.01）, the activity of creatine kinase in the serum and tissue was decreased significantly（P〈0.05）, and supercompensation occurred at 24-48 hours. The levels of muscle glycogen and superoxide dismutase in the group B were significantly higher than those in the control group（P〈0.01）, the activity of creatine kinase in the serum and tissue was significantly lower than that in the control group（P〈0.05）, and supercompensation occurred at 48-60 hours. In the group C, the level of muscle glycogen at 60 hours and the level of superoxide dismutase at 48 hours were significantly higher than those in the control group（P〈0.05 or 0.01）, and other indexes showed no supercompensation. These results indicate that after aerobic exercise, the medium-and high-intensity training will make damage to the muscle structure, especially the heavy training. In the recovery period after exercise, the skeletal muscle morphology shows the best recovery in the medium-intensity group at 48 hours. Under aerobic energy supply of glycogen, the supercompensation of muscle glycogen and aerobic enzyme activity in the medium-intensity training group is obvious, thereafter, medium-intensity training is suitable for glycogen aerobic energy-based movement, and its supercompensation occurs at 48-60 hours after exercise.