Comparative Study Of Lower Strength And Anaerobic Capacity In Adolescent Athletes Using Blood Flow Restriction And Muscle Electrical Stimulation Combined With Low-intensity Resistance Training

Objective:At present,there is relatively little research of blood flow restriction training（BFRT）and electrical muscle stimulation（EMS）on the strength training methods for juvenile athletes.The purpose of this experiment is to explore the adaptive differences between BFRT and EMS combined with low-intensity resistance training on the maximum strength,explosive power and anaerobic capacity of lower limb muscles of juvenile athletes,and provide reference for athletes and coaches to select appropriate training methods at relevant stages to improve juvenile athletes’ability.Methods:This experiment recruited a total of 24 running juvenile athletes（ages between15-18y）,were randomly divided into three groups,eight in each group.Besides daily running training,take 6 weeks,three times a week fitness training.During fitness training,BFRT group and EMS group were combined with 30%1RM resistance training,while CON group only took 30%1RM resistance training.The isokinetic relative peak moment of knee joint flexion and extension at 60°/s,the height of counter movement jump（CMJ）,and the root mean square amplitude（RMS）of surface electromyography during CMJ were measured before and after training.They were recorded as lateral femoral muscle:RMS_VL,rectus femoris:RMS_RF,medial femoral muscle:RMS_VM,and biceps femoris:RMS_BF,30s Wingate anaerobic test peak power（PP）,relative PP,mean power（MP）,relative MP.The test data of BFRT group,EMS group and CON group were statistically analyzed,and the intra-group and inter-group differences among the three groups were compared.Results:The change of the 60°/s isokinetic relative peak moment of the subjects’knee joint before and after training:After 6 weeks of training（left side:1.81±0.58,right side:1.88±0.35）in the BFRT group,there was a significant increase in the isokinetic relative peak moment of bilateral knee flexion compared with that before training（left side:1.55±0.66,right side:1.66±0.27）in the group（P<0.05）,The left knee isokinetic relative peak torque of EMS group after training（1.60±0.61）was significantly higher than that before training（1.35±0.58）（P<0.05）.Changes in CMJ height of subjects before and after training:The CMJ height of the EMS group showed a significant improvement（P<0.05）after 6 weeks of training（36.79±5.13）compared to before training（35.06±5.44）,and the difference（1.73±0.44）before and after6 weeks of training showed a significant difference（P<0.05）compared to the BFRT group（-0.68±0.26）.Changes in surface electromyographic RMS values of subjects before and after the experiment:After 6 weeks of training(right RMS_VL:0.49±0.10,left RMS_RF:0.50±0.15)in the EMS group,there was a significant improvement（P<0.05）compared to before training(right RMS_VL:0.42±0.13,left RMS_RF:0.44±0.12);There was no significant difference（P>0.05）between the BFRT group and the CON group before and after the 6-week experiment.Changes of PP and MP in the 30s Wingate anaerobic capacity test of subjects before and after training:PP and relative PP in the EMS group decreased significantly after 6 weeks of training（PP:677.37±226.15,relative PP:10.89±1.56）compared with those before training（PP:741.81±233.13,relative PP:11.99±1.44）（P<0.01）.MP and relative MP after 6 weeks of training（MP:485.18±148.81,relative MP:7.82±0.86）were significantly lower than those before training（MP:524.38±146.06,relative MP:8.53±0.87）（P<0.05）.After 6weeks of training,there was a significant difference between the EMS group（relative MP difference d:-0.71±0.69）and the BFRT group（relative PP:1.29±1.79,relative MP difference d:-0.10±0.71）in the relative PP and relative MP difference before and after intervention（P<0.05）.Conclusion:Compared with BFRT,6-week EMS combined with low-intensity resistance training has significant advantages in increasing the explosive power of young athletes,but compared with BFRT,its ability of anaerobic energy supply system is affected;The combination of 6-week BFRT,EMS and low-intensity resistance training has no obvious advantages in improving the maximum strength,explosive power and anaerobic capacity of young athletes compared with the low-intensity resistance training alone.