The Effect Of Different Types And Intense Of Adaptive Exercise On Prevention Of Muscle Damage

1 Bases of the researchThere was often muscle damage after training especially after eccentric exercise,but after the second bout of the same exercise there will be no muscle damage or only less damage,this is called repeated bout effect or protective effect of exercise.But whether low intense eccentric exercise or concentric exercise as the first bout exercise can give protection to decrease muscle damage is still now unknown,even there were some researches about these,the results were not agree with each others.Also the mechanisms still not clear,so all these need more researches to be clarified and give answerers.2 Objective and methodsDifferent groups subjects do different types and intense of exercise as the first bout,and do the second bout high intense eccentric 8 days later after the first bout exercise,then observed and compared the muscle damage and the recovery before and after the two bout exercise of all groups,to show us whether low intense eccentric exercise or concentric exercise as the first bout exercise can give protection to decrease muscle damage of the second bout high intense eccentric exercise,and the mechanism of the repeated bout effect.I use groups of SD rats running downhill treadmill quick as high intense eccentric exercise(-16°, 16m/min),rats running downhill treadmill slow as low intense eccentric exercise(-16°,10m/min),and rats running uphill treadmill quick as concentric exercise(+16°,16m/min),and 8 days later all groups have done running downhill treadmill quick(high intense eccentric exercise) as the second bout exercise.Then I took muscle samples,assessed the maximal isometric force of the muscle,checked muscle damage with microscopy and electro-microscopy,checked desmin with imunohistochemistry technique,MDA and SOD in muscle,took blood samples and check CK and LDH in blood,before and after exercise to show muscle damage and recovery. 3 Results and conclusions1)The adaptation of muscle to prevent or decrease muscle damage have positive relative correlation with the intense of adaptive exercise and the degree of muscle damage:as much the intense of exercise and the degree of muscle damage higher as much the adaptation become stronger.2) With direct and indirect evidence,we found that Muscle damage decreased significantly on the second bout high intense eccentric exercise 8 days later compared to the first bout high intense eccentric exercise,this is because of the adaptation(protective effect) we got 8 days later after the first bout high intense eccentric exercise.3)The protective effect of eccentric exercise have relationship with the regeneration of sarcomeres and the increase of numbers of sarcomeres in series,also have relationship with the change of the redox environment inside muscle,and the change of the redox environment inside muscle is possible one of the causes of the regeneration of sarcomeres.4) Low intense eccentric exercise can give protection to decrease muscle damage of the second bout high intense eccentric exercise 8 days later.5) One time concentric exercise as the first bout can not prevent or decrease muscle damage for the second bout eccentric exercise 8 days later.6) One time concentric exercise as the first bout can give out some adaptation to decrease muscle damage or muscle fatigue for the second bout concentric exercise 8 days later.7) RBE is the adaptive effect we got on the repeated bout exercise with less or no muscle damage and the recover and regeneration of sarcomere and increase of the number of sarcomere in series after first bout high intense,also the adaptation against oxidative stress inside muscle after the first bout who make muscle fibers stronger against damage,also the recover and the strength of cell membrane who happened after first bout and make it not easy to be destroyed are mechanisms of RBE.