Influence Of Plyometric Training On Lower Limb Strength Of Male Cross-Country Skiers In Shaanxi Province

Research objectives: Cross-country skiing has a long history and is a classic event at the Winter Olympics.It is competed in various forms,including relay,chase,team and individual events.The competition venue is complex and changeable,which has high requirements on the strength,speed and endurance of athletes.For snow events like cross-country skiing,the current mainstream strength training method is still based on the traditional resistance training,but the fast strength and explosive power training based on the plyometric training is extremely lacking.Therefore,the purpose of this study is to: 1.Explore the influence of plyometric training on lower limb strength quality of male cross-country skiers.2.Compare the difference in effect of plyometric training and traditional resistance training in improving various strength qualities of lower limbs.3.Explore the influence of plyometric training on special results of cross-country skiing.Research methods: This paper adopts the method of literature,expert interview,questionnaire,experiment and mathematical statistics.In the National Snow and Ice Training Center of Ankang City,Shaanxi Province,20 male cross-country skiers with Level2 and above were randomly divided into experimental group and control group,and underwent an 8-week lower extremity strength training intervention.The experimental group underwent plyometric training,and the control group underwent traditional resistance training.Before and after intervention,the lower limb strength indexes of the two groups were tested,including 1RM squat,constant ankle,knee peak force data,standing long jump,vertical jump in place,maximum number of self-weight squat,80%RM maximum number of squat,constant ankle,knee fatigue index,and 10 KM traditional pulley.The test results were discussed and analyzed in detail.Results :(1)after 8 weeks of training intervention,in the maximum strength indicators,the experimental group and the control group had significant improvement in 1RM squat,equal ankle speed,and peak force of knee joint(P < 0.05),but the experimental group had greater improvement than the control group,and the effect size(ES)was also greater than the control group.At the same time,post-test experimental data showed that there were significant differences between the experimental group and the control group in 1RM squatting,equal-speed ankle and knee peak force data(P= < 0.05).(2)In the fast strength indexes,the experimental group improved both standing long jump and vertical vertical jump with significant difference(P < 0.05),but the experimental group improved significantly than the control group,and the effect size(ES)was also larger than the control group.At the same time,post-test experimental data showed that there were significant differences in standing long jump and vertical vertical jump between the experimental group and the control group(P= < 0.05).(3)In the strength endurance indexes,the maximum number of dead weight squat,isokinetic ankle and knee fatigue indexes in the experimental group showed slight improvement but no significant difference(P= > 0.05),while the maximum number of80%RM squat increased significantly(P= < 0.05),with moderate effect level(ES)> 0.25.There was a significant difference in the increase of the maximum weight squat times and80%RM squat times in the control group(P= < 0.05),and the moderate effect level(ES)was > 0.25.There was no significant difference in the increase of isokinetic ankle and knee fatigue indexes(P= > 0.05),and the increase of the above data in the control group was greater than that in the control group.According to the post-test data,there were no significant differences between the experimental group and the control group in the maximum number of dead weight squats,the maximum number of 80%RM squats,the isokinetic ankle and knee fatigue indexes(P= > 0.05).(4)Specific ability index: the experimental group and the control group made significant progress with significant difference(P < 0.05),but the experimental group made greater progress than the control group,and the effect size(ES)was also greater than the control group.Post-test data showed that there was no significant difference between the experimental group and the control group of 10 KM traditional pulley(P= > 0.05).Conclusions: 1.plyometric training can be used as an effective means to strengthen the maximum strength of lower limbs of cross-country skiers.2.plyometric training is more effective for strengthening the lower limb fast strength and explosive power of cross-country skiers.3.plyometric training is inferior to traditional resistance training in increasing the lower extremity strength and endurance of cross-country skiers.4.plyometric training is better than traditional resistance training in improving the performance and performance of cross-country skiing...