A Study On The Effect Of Post-activation Potentiation On The Explosive Power Of Lower Limbs In Male Long Jumpers Aged 18-19 Years

Objective: In this study,we investigated the long-term effect of post-activation potentiation on explosive power with reference to training weeks,at the same time,we set 70% 1RM,80% 1RM and 90% 1RM post-activation load stimuli for comparative study to prove the best effect of post-activation potentiation on explosive power,to provide a basis for improving the level of explosive power training of male long jumpers’ lower limbs.The study was conducted to find out the best post-activation potentiation stimulus intensity for explosive strength and to provide a reference for improving the explosive strength of male long jumpers.Methods: After preliminary screening,24 long jumpers eligible for this study were randomly selected and randomly divided into 4 training groups,including 3experimental groups(70% 1RM,80% 1RM,and 90% 1RM activation groups,6 in each experimental group,18 in total)and 1 control group(80% 1RM control group,6in total).The experimental group performed 5 sets of 1 70% 1RM,80% 1RM,and90% 1RM squat activation and daily training after regular warm-up;the control group performed 5 sets of 1 80% 1RM squat exercise after daily training.A stopwatch,tape measure,Gym Aware strength power testing system and BTS FREEMG300 wireless surface EMG tester were used as measurement tools to measure the kinematic indexes(30m run,standing long jump,long jump,deep squat 1RM weight),kinetic indexes of squat jump(peak power,peak velocity,reverse height)and changes in squat jump EMG data of the subjects before and after the 8-week activation intervention(rectus femoris,lateral femoris,medial femoris,and biceps femoris integral EMG values).Using repeated measures two-way ANOVA,the differences between the four groups before and after performing their own interventions were compared to themselves,as well as between the different groups after the interventions,with a significant difference of P<0.05.Results:(1)Results of kinematic index tests after the experimentThe greatest improvement was in the 80% 1RM activation group,which showed significant(P<0.05)improvement in long jump and squat 1RM weight,and extremely significant(P<0.01)improvement in 30 m and standing long jump after the experiment.This was followed by the 70% 1RM activation group,which showed a significant increase in 1RM weight in the deep squat(P<0.05)and a highly significant increase in the vertical jump(P<0.01).In the other 90% 1RM activation group,only the deep squat 1RM weight showed a significant improvement(P<0.05);the 80% 1RM control group showed no significant difference from the pre-experimental measurement in all indexes.Post-experimental controls showed that the 80% 1RM-activated group showed a significant improvement in the vertical long jump compared to the 70%1RM-activated group(P<0.05);the 80% 1RM-activated group showed a significant improvement in the 30 m compared to the 90% 1RM-activated group(P<0.05);and the 80% 1RM-activated group showed a significant improvement in the vertical long jump compared to the 80% 1RM control group(P<0.05).(2)Results of kinetic index test after the experimentThe greatest improvement was observed in the 80% 1RM activation group,where the peak power and peak velocity increased significantly(P<0.05)and the reverse height increased significantly(P<0.01),followed by the 70% 1RM activation group,where only the reverse height increased significantly(P<0.05).The other 90%1RM activation group and the 80% 1RM control group showed no significant difference in all indicators from the pre-experimental test.Post-experimental controls between groups showed that the 80% 1RM activation group showed a significant increase in peak velocity and reverse height(P<0.05)and an extremely significant increase in peak power(P<0.01)compared to the 80% 1RM control group.(3)Results of electromyographic index test after the experimentThe 80% 1RM activation group showed the greatest increase,with significant increases in the EMG values of all four muscle scores after the experiment(P<0.05),followed by the 70% 1RM activation group,with significant increases in the EMG values of the rectus and lateral femoral muscles(P<0.05)and extremely significant increases in the EMG values of the medial femoral muscles(P<0.01).In the 90%1RM activation group and the 80% 1RM control group,there was no significant increase in EMG values except for the lateral femoral integral EMG values(P<0.05).Post-experimental controls showed that: compared to the 70% 1RM activation group,the 80% 1RM activation group showed a significant increase in rectus femoris integral EMG values(P<0.05);compared to the 90% 1RM activation group,the 80%1RM activation group showed a significant increase in rectus femoris integral EMG values(P<0.05);compared to the 80% 1RM control group,the 80% 1RM activation group showed a significant increase in medial femoral and biceps femoris integral EMG values(P<0.05).compared with the 80% 1RM control group.Conclusions: The post-activation potentiation enhances the degree of muscle activation,muscle recruitment,optimizes the neuromuscular control of the lower limbs,and improves the explosive power of the lower limb muscles;compared with the 70% 1RM and 90% 1RM activation groups,the 80% 1RM activation group induces a greater enhancement effect,while inducing less fatigue effect,which in turn shows the optimal enhancement effect.Recommendations: In the post-activation potentiation to guide the training process of long jump explosive power,the post-activation potentiation can be induced by using 80% 1RM squat activation intensity.We should also pay close attention to individual differences to prevent the activation intensity from being too high,leading to increased muscle fatigue and affecting the subsequent normal training.