The Effects Of 8 Weeks Of Medium-intensity Or High-intensity Strength Training On Lower-body Strength And Specific Athletic Ability In Adolescent Cyclists

Objective: To compare the effects of two different intensities of strength training performed during winter training concurrently with cycling-specific training on the lower limb strength and cycling-specific athletic ability of youth cyclists.Methods: Twenty athletes(14 males and 6 females)from the cycling team of Minhang District Junior School in Shanghai were selected as subjects.They were paired according to gender,age,height,weight,and maximum strength,and then randomly divided into high-intensity strength training group(HI-RT group;7 males,3 females)and medium-intensity strength training group(MI-RT group;7 males,3 females).The experiment was conducted for a total of 8 weeks of intervention,which included deep squats,overhead rowing,Romanian Deadlift and bench press.Both groups of athletes simultaneously performed strength training at the same location on Mondays and Thursdays during winter training.the HI-RT group performed strength training using75%-85% 1RM(4 sets per movement,4-6 reps per set depending on the weight);the MI-RT group performed strength training using 50%-60% 1RM intensity(4 sets per movement,8-12 reps per set depending on the weight).The CMJ test,SJ test and IMTP test were performed in the 1st and 10 th week of the experiment to reflect the changes in the athletes’ maximum lower limb strength and explosive power;the 20 min all-out ride,inter-row dive ride and in situ start ride were performed to reflect the changes in the athletes’ specific athletic ability;the 30 s Wingate test,VO2 max test and cycling economy test were performed to reflect The 30 s Wingate test,VO2 max test and cycling economy test were conducted to reflect the changes of important factors influencing athletes’ special athletic ability.Results:1.Changes in lower limb strength:(1)The changes in mean CMJ power and relative mean power in the HI-RT group were not statistically significant;the increases in CMJ height(p<0.001),CMJ peak power(p=0.04),and CMJ relative peak power(p=0.022)in the post-test were all significant compared with the pre-test;the changes in CMJ height,CMJ peak power,CMJ mean power,and CMJ relative peak power in the MI-RT group were statistically significant.power,CMJ peak power,CMJ average power,CMJ relative peak power,and CMJ relative average power did not show significant changes.(2)The changes in SJ mean power and relative mean power in the HI-RT group were not statistically significant,and the increases in SJ height(p<0.001),SJ peak power(p<0.001)and SJ relative peak power(p<0.001)in the posttest were statistically significant compared with the pretest;only SJ height(p=0.004)in the MIRT group showed significant changes before and after the intervention,and SJ peak power and SJ relative peak power(p<0.001)were statistically significant.peak power,SJ mean power,SJ relative peak power and SJ relative mean power did not show significant changes.(3)The increase in IMTP maximal power(p=0.011)and relative maximal power(p=0.01)in the HI-RT group was significant in both post-test and pretest;no significant changes in IMTP maximal power and relative maximal power were observed in the MI-RT group before and after the intervention.2.Changes in cyclingspecific exercise capacity:(1)The HI-RT group(p<0.001)and the MI-RT group(p=0.001)showed significant changes in IMTP maximal power and relative maximal power.RT group(p=0.001)both had significant changes in mean power for 20 min allout riding in post-test compared to pre-test;(2)HI-RT group showed significant changes in inter-travel sprint riding speed(p<0.001)and in situ start riding speed(p<0.001)in post-test compared to pre-test;MI-RT group showed no changes in intertravel sprint riding and in situ start riding before and after the intervention 3.changes in important factors influencing cycling-specific exercise capacity: peak and mean power,maximal oxygen uptake,and maximal aerobic power in the 30 s Wingate test in the HI-RT group were not statistically significant before and after the intervention,and increases in cycling economy(p=0.006)and cycling efficiency(p<0.001)were statistically significant in the post-test compared to the pre-test;The changes in peak and mean power,maximal oxygen uptake,maximal aerobic power,cycling economy and cycling efficiency in the 30 s Wingate test in the MI-RT group were not statistically significant before and after the intervention.Conclusions:1.High-intensity strength training for 8 weeks,twice a week,significantly improved lower body maximal strength and explosive power in youth cyclists,whereas moderate-intensity strength training did not significantly improve lower body maximal strength and explosive power in youth cyclists.2.In youth cyclists,high-intensity strength training performed concurrently with cycling-specific training was more effective than moderate-intensity strength training.High-intensity strength training better improved lower extremity strength and explosive power,optimized cycling economy and cycling efficiency,and thus increased long-distance cycling,maximal speed,and speed endurance capacity in youth cyclists.