***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Ramírez-Campillo , R , Gallardo , F , Henriquez-Olguín , C , Meylan , CMP , Martínez , C , Álvarez , C , Caniuqueo , A , Cadore , EL , and Izquierdo , M. Effect of vertical , horizontal , and combined plyometric training on explosive , balance , and endurance performance of young soccer players . J Strength Cond Res 29(7 ) : 1784–1795 , 2015—The aim of this study was to compare the effects of 6 weeks of vertical , horizontal , or combined vertical and horizontal plyometric training on muscle explosive , endurance , and balance performance .  Forty young soccer players aged between 10 and 14 years were r and omly divided into control ( CG ; n = 10 ) , vertical plyometric group ( VG ; n = 10 ) , horizontal plyometric group ( HG ; n = 10 ) , and combined vertical and horizontal plyometric group ( VHG ; n = 10 ) . Players performance in the vertical and horizontal countermovement jump with arms , 5 multiple bounds test ( MB5 ) , 20-cm drop jump reactive strength index ( RSI20 ) , maximal kicking velocity ( MKV ) , sprint , change of direction speed ( CODS ) , Yo-Yo intermittent recovery level 1 test ( Yo-Yo IR1 ) , and balance was measured . No significant or meaningful changes in the CG , apart from small change in the Yo-Yo IR1 , were observed while all training programs result ed in meaningful changes in explosive , endurance , and balance performance . However , only VHG showed a statistically significant ( p ⩽ 0.05 ) increase in all performance test and most meaningful training effect difference with the CG across tests . Although no significant differences in performance changes were observed between experimental groups , the VHG program was more effective compared with VG ( i.e. , jumps , MKV , sprint , CODS , and balance performance ) and HG ( i.e. , sprint , CODS , and balance performance ) to small effect . The study demonstrated that vertical , horizontal , and combined vertical and horizontal jumps induced meaningful improvement in explosive actions , balance , and intermittent endurance capacity . However , combining vertical and horizontal drills seems more advantageous to induce greater performance improvements Abstract Complex training ( CXT ) is the result of a combination of strength and plyometric exercises in the same session . This method has recently been used in the preparation of athletes of different sports . The aim of the present study was to observe the acute effects of a CXT program of 6 weeks : i ) on agility with the ball , sprinting and the efficiency of crossing and shooting in youth soccer players ; ii ) and the influence of the number of CXT sessions per week ( one vs. two ) . Sixteen youth male soccer players were r and omly divided into three groups : a group that performed one weekly CXT session ( GCT1 , n = 5 , age : 13.80 ± 0.45 years ) ; or a group that performed two weekly CXT sessions ( GCT2 , n = 5 , age : 14.20 ± 0.45 years ) ; or a control group that did not perform the CTX ( n = 6 , age : 14.20 ± 0.84 years ) . All groups maintained their regular soccer training sessions . No significant interactions were found between GCT1 and GCT2 in all variables . Significant statistical differences were identified ( F = 1139 , p = 0.02 , μp2 = 0531 ) in the pre-test versus post-test , for both experimental groups , in shot effectiveness . In conclusion , the CXT program proved to be an effective method in boosting abilities and motor skills associated with soccer among young athletes , particularly in increasing shot effectiveness Abstract Santos , EJAM and Janeira , MAAS . The effects of resistance training on explosive strength indicators in adolescent basketball players . J Strength Cond Res 26(10 ) : 2641–2647 , 2012—The purpose of this study was to assess the effects of a lower- and upper-body 10-week in-season resistance training program on explosive strength development in young basketball players . Twenty-five adolescent male athletes , aged 14–15 years old , were r and omly assigned to an experimental group ( EG ; n = 15 ) and a control group ( CG ; n = 10 ) . The subjects were assessed at baseline and after training for  squat jump ( SJ ) , countermovement jump ( CMJ ) , Abalakov test , drop jump , and seated medicine ball throw ( MBT ) . The EG showed significant increases ( p < 0.05 ) in all the variable scores . Conversely , the CG significantly decreased ( p < 0.05 ) in SJ , CMJ , and Abalakov test scores and significantly increased in the results of MBT test ( p < 0.05 ) . The groups were similar on pretest , but significant differences ( p < 0.05 ) occurred on posttest in all the variables . The results of this study show that a 10-week in-season resistance training program with moderate volume and intensity loads increased vertical jump and MBT performance in adolescent male basketball players . Coaches should know that such a short resistance training program specifically design ed for young basketball players induce increased explosivity levels , which are essential to a better basketball performance , with no extra overload on adolescents ' skeletal muscle development Abstract Ferrete , C , Requena , B , Suarez-Arrones , L , and Sáez de Villarreal , E. Effect of strength and high-intensity training on jumping , sprinting , and intermittent endurance performance in prepubertal soccer players . J Strength Cond Res 28(2 ) : 413–422 , 2014—The purpose of this study was to examine the effects of a 26-week on-field combined strength and high-intensity training on the physical performance capacity among prepubertal soccer players who were undertaking a competitive phase of training . Twenty-four prepubertal soccer players between the age of 8 and 9 years were r and omly assigned to 2 groups : a control ( C ; n = 13 ) and an experimental group ( S ; n = 11 ) . Both groups performed an identical soccer-training program , whereas the S group also performed combined strength and high-intensity training before the soccer-specific training . The 15-m sprint time ( seconds ) , countermovement jump ( CMJ ) displacement , Yo-Yo intermittent endurance test ( Yo-Yo IE ) , and Sit and Reach flexibility were each measured before ( baseline ) and after 9 ( T2 ) , 18 ( T3 ) , and 26 weeks ( posttest ) of training . There were no significant differences between the groups in any of the variables tested at baseline . After 26 weeks , significant improvements were found in the CMJ ( 6.72 % ; effect size [ ES ] = 0.37 ) , Yo-Yo IE ( 49.57 % , ES = 1.39 ) , and Flexibility ( 7.26 % ; ES = 0.37 ) variables for the S group . Conversely , significant decreases were noted for the CMJ ( −10.82 % ; ES = 0.61 ) and flexibility ( −13.09 % ; ES = 0.94 ) variables in the C group . A significant negative correlation was found between 15-m sprint time and CMJ ( r = −0.77 ) and Yo-Yo IE ( r = −0.77 ) in the S group . Specific combined strength and high-intensity training in prepubertal soccer players for 26 weeks produced a positive effect on performance qualities highly specific to soccer . Therefore , we propose modifications to current training methodology for prepubertal soccer players to include strength and high-intensity training for athlete preparation in this sport Bishop , DC , Smith , RJ , Smith , MF , and Rigby , HE . Effect of plyometric training on swimming block start performance in adolescents . J Strength Cond Res 23(7 ) : 2137 - 2143 , 2009-This study aim ed to identify the effect of plyometric training ( PT ) , when added to habitual training ( HT ) regimes , on swim start performance . After the completion of a baseline competitive swim start , 22 adolescent swimmers were r and omly assigned to either a PT ( n = 11 , age : 13.1 ± 1.4 yr , mass : 50.6 ± 12.3 kg , stature : 162.9 ± 11.9 cm ) or an HT group ( n = 11 , age : 12.6 ± 1.9 yr , mass : 43.3 ± 11.6 kg , stature : 157.6 ± 11.9 cm ) . Over an 8-week preseason period , the HT group continued with their normal training program , whereas the PT group added 2 additional 1-hour plyometric-specific sessions , incorporating prescribed exercises relating to the swimming block start ( SBS ) . After completion of the training intervention , post-training swim start performance was reassessed . For both baseline and post-trials , swim performance was recorded using videography ( 50Hz Canon MVX460 ) in the sagital plane of motion . Through the use of Silicon Coach Pro analysis package , data revealed significantly greater change between baseline and post-trials for PT when compared with the HT group for swim performance time to 5.5 m ( −0.59 s vs. −0.21 s ; p < 0.01 ) and velocity of take-off to contact ( 0.19 ms−1 vs. −0.07 ms−1 ; p < 0.01 ) . Considering the practical importance of a successful swim start to overall performance outcome , the current study has found that inclusion of suitable and safely implemented PT to adolescent performers , in addition to HT routines , can have a positive impact on swim start performance The purpose of the current study was to evaluate the transferability of 2 different resistance training protocol s on service velocity and its precision consistency in junior tennis players . Thirty-six male athletes ( 15.03 ± 1.64 years ) were r and omly assigned to a machine-based resistance-training group ( RG , n = 12 ) , a plyometric training group ( PG , n = 12 ) , and a control group ( CG , n = 12 ) . For a period of 8 weeks , both intervention groups resistance trained 2 days per week in addition to their regular tennis training , whereas the CG had no extra training . Mean service velocity over 20 maximum-velocity serves increased significantly more in PG ( 3.78 % ; p < .05 ) when compared with CG , whereas no such changes could be found in the RG ( 1.18 % ; p > .05 ) . Service precision did not change from pre- to posttest in all three groups ( p > .05 ) . Only the plyometric training program tested , improved mean service velocity over 20 maximum-velocity serves in junior tennis players but did not affect service precision Abstract Chelly , MS , Hermassi , S , and Shephard , RJ . Effects of in-season short-term plyometric training program on sprint and jump performance of young male track athletes . J Strength Cond Res 29(8 ) : 2128–2136 , 2015—We studied the effect of supplementing normal in-season training by a 10-week lower limb plyometric training program ( hurdle and depth jumping ) , examining measures of competitive potential ( peak power output [ PP ] , sprint running velocity , squat jump [ SJ ] , countermovement jump [ CMJ ] , drop jump [ DJ ] , and lower limb muscle volume ) .  The subjects ( 27 male track athletes , aged 11.9 ± 1.0 years ; body mass : 39.1 ± 6.1 kg ; height : 1.56 ± 0.02 m ; body fat : 12.8 ± 4.4 % ) were r and omly assigned between a  control ( normal training ) group ( C ; n = 13 ) and an experimental group ( E ; n = 14 ) who also performed plyometric training 3 times per week . A force-velocity ergometer test determined PP and SJ , and an Optojump apparatus evaluated CMJ height and DJ ( height and power ) . A multiple-5-bound test assessed horizontal jumping , and video-camera analyses over a 40-m sprint yielded velocities for the first step ( VS ) , the first 5 m ( V5 m ) , and between 35 and 40 m ( Vmax ) . Leg muscle volume was estimated anthropometrically . Experimental group showed gains relative to C in SJ height ( p < 0.001 ) ; CMJ height ( p < 0.01 ) ; DJ height and power relative to body mass ( p < 0.01 for both ) ; and all sprint velocities ( p < 0.01 for VS and V5 m , p ⩽ 0.05 for Vmax ) . There was also a significant increase ( p < 0.01 ) in thigh muscle volume , but leg muscle volume , thigh cross-sectional area , and PP remained unchanged . We conclude that adding plyometric training improved important components of athletic performance relative to st and ard in-season training in young runners Meylan , C and Malatesta D. Effects of in-season plyometric training within soccer practice on explosive actions of young players . J Strength Cond Res 23(9 ) : 2605 - 2613 , 2009-In soccer , explosive actions such as jumping , sprinting , and changes of direction are essential to optimal performance not only in adults , but also in children 's games . The purpose of the present investigation was to determine the influence of a short-term plyometric training within regular soccer practice on explosive actions of early pubertal soccer players during the in-season . Fourteen children ( 13.3 ± 0.6 years ) were selected as the training group ( TG ) and 11 children ( 13.1 ± 0.6 years ) were defined as the control group ( CG ) . All children 
    Output:
    
SUMMARY / CONCLUSIONS Resistance training is an effective method to enhance muscle strength and jump performance in youth athletes , moderated by sex and resistance training type .