Two Load Intensity Contrast Training For Sprinters Study On The Effects Of Lower Extremity Explosiveness

Contrast training alternates between groups with high and low load exercises,and the biomechanics of light and heavy load exercises are similar.According to relevant studies,contrast training can effectively improve the muscle strength and explosiveness of athletes’ lower limbs in other events,but there are few studies on what kind of load intensity is used to improve the explosiveness of sprinters.In this experiment,appropriate training methods were selected according to the characteristics of sprint special strength,and the effect of 75%-85%1RM load and 85%-95%1RM load on the lower limb explosiveness of sprinters was explored with reference to the physiological basis of contrast training.Research Methods: The literature method and questionnaire method were used to select the training action combination and lower limb explosiveness test index with special characteristics of load sprinting.The experimental method was used to carry out practical research,and the 12 sprinters in the sprinting group of the Wuhan Institute of Physical Education Athletics Academy were divided into two groups,with 75%-85% 1RM load comparative training in experimental group I and 85%-95% 1RM load comparative training in experimental group II.The measurement method actually measures the maximum strength and explosive power indicators of the two experimental groups.Finally,mathematical statistics were used to statistically analyze the maximum strength and explosiveness indexes before and after the two experimental groups.Experimental results and analysis:(1)After the experiment,there were significant differences in the weight of the 1RM squat and the performance of the 30 m acceleration run in the group(P<0.05),but there was no significant difference between the groups(P>0.05).(2)After the experiment,there were significant differences in standing long jump score,squat jump(CMJ)height and deep jump(DJ)height(P<0.05),but there was no significant difference between the two groups(P>0.05).(3)After the experiment,there was a significant difference in the height of static squat jump(SJ)in the group(P<0.05),but there was no significant difference between the groups(P>0.05).(4)There was no significant difference in the increase in 1RM squat weight and 30 m acceleration running performance between the two groups(P>0.05),possibly because the two loads were in the optimal load intensity range for developing maximum muscle strength and the 30 m acceleration performance mainly depended on the maximum strength of the athlete.There was a significant difference in the increase of standing long jump performance,squat jump(CMJ)height and deep jump(DJ)height between the two groups(P<0.05),and the improvement of 75%-85% 1RM load contrast training was greater than 85%-95% 1RM load contrast training,possibly because75%-85% 1RM load contrast training made the muscle centrifugal-centripetal contraction coupling time less than 85%-95% 1RM load contrast training.There was a significant difference in the increase in squat jump(SJ)height between the two groups(P<0.05),and the improvement of 85%-95% 1RM load contrast training was greater than that of 75%-85%1RM load contrast training,which may be because 85%-95% 1RM load contrast training compared with 75%-85% 1RM load contrast training can recruit more exercise units in a short time.Conclusions:(1)Both load intensity comparison training can significantly improve the 1RM squat weight and 30 m acceleration running performance,and there is no significant difference in the improvement of 1RM squat weight and 30 m acceleration running performance between the two load intensity comparison training.(2)Both kinds of load intensity contrast training can significantly improve the standing long jump performance,squat jump(CMJ)height and deep jump(DJ)height,and there is a significant difference in the growth range of these three explosiveness indicators,indicating that the effect of 75%-85% 1RM load contrast training is better than that of 85%-95% 1RM load contrast training.(3)Both kinds of load intensity contrast training can significantly increase the height of static squat jump(SJ),and there is a significant difference in the increase of static squat jump(SJ)height compared with the two load intensity contrast training,indicating that the effect of 85%-95% 1RM load contrast training is better than 75%-85% 1RM load contrast training.(4)Comprehensive analysis of a number of explosiveness indicators shows that 75%-85% 1RM load contrast training is better than 85%-95% 1RM load contrast training for improving the lower limb explosiveness of sprinters.