Experimental Study On The Effects Of Different Load-bearing Plyometric Training On The Lower Limbs Explosive Force Of Sprinters

Explosiveness training is one of the main contents of sprint training.How to improve the strength and explosiveness of sprinters efficiently is a widespread concern of coaches and researchers.he Plyometric training is an effective way to develop explosiveness.Some researches show that the combination of load-bearing and Plyometric training has achieved good results.But at present,there are few researches on the Plyometric training with different load-bearing methods.This paper uses the methods of literature,expert interview,questionnaire,experiment and mathematical statistics.The subjects of the experiment are sprinters from China Athletics college,Beijing Sport University 2018.Based on the fast strength training method of Sprinters’ lower limbs,the subjects are randomly divided into two groups.The two groups are experimented with the fast stretching compound exercises of different load-bearing methods,he experimental group followed the principle of priority to adopt the compound exercise,that is,to carry out the weight-bearing exercise first,and then to carry out the Plyometric training.The control group followed the principle of immediacy to use the Plyometric training with weight-bearing,that is,to carry out the Plyometric training when carrying the weight.After the experiment,a variety of lower limb muscle strength test methods were used to comprehensively evaluate the lower limb explosiveness of athletes.According to the results of the experiment,this paper explores the effect and difference between the compound exercise and the Plyometric training with weight-bearing,After 12 weeks of experiment,the following conclusions were obtained:1.After 12 weeks of experiment,on the physical quality index,There were significant differences in the experimental group(compound exercise)before and after the experiment.There were significant differences in other indexes in the control group (Plyometric training with weight-bearing)except that there was no significant difference before and after the 1RM squat experiment.This shows that the compound exercise has a good effect on the development of explosive force and maximum force,and the effect of the Plyometric training with weight-bearing is obvious in the development of explosiveness,but not obvious in the development of maximum strength.2.After 12 weeks of experiment,there were significant differences between the experimental group(compound exercise)and the control group(Plyometric training with weight-bearing)increased significantly in the four indexes of the instantaneous force value,the instantaneous speed of leaving the platform,the height of takeoff and the relative maximum power,This shows that the compound exercise and Plyometric training with weight-bearing have better training effect in the development of explosiveness.3.After the experiment,through the test of body quality index and biomechanical index,it is found that the difference between the experimental group(compound exercise)and the control group(Plyometric training with weight-bearing)is significant before and after the experiment of standing triple jump and 1RM squat,And the compound exercise growth rate is large,which shows that the compound exercise has better effect in the development of standing triple jump and 1RM squat;No difference was found in other indexes,but the improvement range of each index in the experimental group was higher than that in the control group.4.After the experiment,through the test and analysis of isokinetic muscle force of two groups under different angular velocity,it is found that: with the increase of angular velocity(60 °-240 °),the peak moment and relative peak moment of flexion and extension decrease,the average power of flexion and extension increases,and the ratio of flexion and extension tends to increase;There was no significant difference in peak moment,relative peak moment,average power and ratio of flexion and extension at the same speed,but the experimental group(compound exercise)was better than the control group(Plyometric training with weight-bearing).