***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 Purkhús , E , Krustrup , P , and Mohr , M. High-intensity training improves exercise performance in elite women volleyball players during a competitive season . J Strength Cond Res 30(11 ) : 3066–3072 , 2016—Elite women volleyball players ( n = 25 ; mean ± SD : age , 19 ± 5 years ; height , 171 ± 7 cm ; weight , 63 ± 10 kg ) volunteered to participate in the study . They were r and omized into a high-intensity training ( HIT ; n = 13 ) group and a control ( CON ; n = 12 ) group . In addition to the normal team training and games , HIT performed 6–10 × 30-seconds all-out running intervals separated by 3-minute recovery periods 3 times per week during a 4-week in-season period whereas CON only completed the team training sessions and games . Preintervention and postintervention , all players completed the  arrowhead agility test ( AAT ) , a repeated sprint test  ( RST ; 5 × 30 meters separated by 25 seconds of recovery ) , and the Yo-Yo Intermittent Recovery level 2 test ( Yo-Yo IR2 ) followed by a-10 minute rest period and the Yo-Yo IR1 test . Mean running distance during HIT in week 1 was 152 ± 4 m and increased ( p ⩽ 0.05 ) by 4.6 % ( 159 ± 3 m ) in week 4 . The AAT performance improved ( p ⩽ 0.05 ) by 2.3 % ( 18.87 ± 0.97–18.44 ± 1.06 seconds ) and RST by 4.3 % postintervention in the HIT group only . Baseline RST fatigue index was 7.0 ± 2.9 and 6.2 ± 5.0 % in HIT and CON , respectively , but was lowered ( p ⩽ 0.05 ) to 2.7 ± 3.0 % posttraining in HIT and remained unaltered in CON ( 5.5 ± 5.0 % ) . In HIT , Yo-Yo IR2 and Yo-Yo IR1 performance improved by 12.6 and 18.3 % postintervention , respectively , with greater ( p ⩽ 0.05 ) Yo-yo IR1 change scores than in CON . In conclusion , additional high-intensity in-season training performed as interval running improved agility , repeated sprint ability , and high-intensity intermittent exercise performance in elite women volleyball players Abstract Campos-Vazquez , MA , Boza , SR , Toscano-Bendala , FJ , Leon-Prados , JA , Suarez-Arrones , L , and Gonzalez-Jurado , JA . Comparison of the effect of repeated-sprint training combined with two different methods of strength training on young soccer players . J Strength Cond Res 29(3 ) : 744–751 , 2015—The aim of this study was to assess the effect of combining repeated-sprint training with 2 different methods of muscle strength training on physical performance variables in young players . Twenty-one soccer players with mean ( ±SD ) age of 18.1 ( ±0.8 ) years , weight 69.9 ( ±6.5 ) kg , and height 177.1 ( ±5.7 ) cm , and competing in U-19 category , were r and omly assigned to 2 experimental groups : squat group ( SG : n = 10 ) and take-off group ( TG : n = 11 ) . Intervention in both groups consisted of the combination of a weekly session of repeated-sprint training ( the same for both groups ) , with 2 weekly sessions of strength training ( different for each group ) , for 8 weeks in the final period of the season . The strength sessions for the SG consisted of conducting a series of full squats executed at maximum velocity in the concentric phase . Intervention in the TG was the performance of 2 specific strength exercises ( take-offs and change of direction ) , with measurements taken before and after consideration of the following variables : repeated-sprint ability ( RSA ) , yo-yo intermittent recovery test level 1 ( YYIRT1 ) , countermovement jump ( CMJ ) , and average velocity in full squat progressive loads test . The SG improved CMJ height in 5.28 % ( p ⩽ 0.05 ) and FS37.5 - 47.5 - 67.5 ( p ⩽ 0.05 ) , whereas the TG improved FS17.5 - 27.5 - 37.5 - 47.5 - 67.5 ( p ⩽ 0.05 ) . There were no significant changes in the values of RSA or YYIRT1 in either group . The results seem to show that the combination of a weekly session of repeated-sprint training with 2 weekly sessions of strength training could be an insufficient stimulus to improve RSA in the final period of the season BACKGROUND The present study assessed the optimal moment of the day for repeated-sprint training in the fasted state during Ramadan . METHODS Thirty amateur soccer players were r and omly assigned to a morning training group ( MTG , training at ~08:00 a.m. , N.=10 ) , an evening training group ( ETG , training around 06:00 p.m. , N.=10 ) , and a control group ( N.=10 ) . Training sessions , conducted on alternate days , consisted of 3 sets of 6 × 40-m shuttle sprints ( 2 × 20 m with 180 ° direction changes ) . A 20-second passive recovery and a 4-minute passive recovery were allowed between repetitions and sets , respectively . Before and after Ramadan , performance was assessed at both 08:00 a.m. and 06:00 p.m. by Countermovement Jump ( CMJ ) , Repeated-Sprint Test ( RST ) , and Yo-Yo Intermittent Recovery Test Level 1 ( YYIRT1 ) . RESULTS After Ramadan , YYIRT1 performances were enhanced for both groups in the morning ( 7.82 % and 6.29 % for MTG and ETG , respectively , P<0.05 ) , and in the evening ( 6.61 % and 11.20 % , respectively , P<0.05 ) . Relative changes in YYIRT1 ( P=0.33 ) and RST ( -2.13 % and -3.44 % for MTG and ETG , respectively , P=0.49 ) at the specific time of training were similar for both groups . No differences were observed in CMJ performances before and after Ramadan for any group ( P>0.05 ) . CONCLUSIONS Morning or evening repeated-sprint training conducted in the fasted state during Ramadan enhanced soccer-specific endurance similarly The aims of this study were to ( 1 ) determine the reproducibility of sub-maximal and maximal versions of the Yo – Yo intermittent endurance test level 2 ( Yo – Yo IE2 test ) , ( 2 ) assess the relationship between the Yo – Yo IE2 test and match performance and ( 3 ) quantify the sensitivity of the Yo – Yo IE2 test to detect test – retest changes and discriminate between performance for different playing st and ards and positions in elite soccer . Elite ( n = 148 ) and sub-elite male ( n = 14 ) soccer players carried out the Yo – Yo IE2 test on several occasions over consecutive seasons . Test – retest coefficient of variation ( CV ) in Yo – Yo IE2 test performance and heart rate after 6 min were 3.9 % ( n = 37 ) and 1.4 % ( n = 32 ) , respectively . Elite male senior and youth U19 players  Yo – Yo IE2 performances were better ( P < 0.01 ) than elite youth U16s and sub-elite players ( 2,603 ± 451 and 2,534 ± 549 vs. 1,855 ± 535 vs. 1,749 ± 382 m ) . The intra- and inter-season CV for Yo – Yo IE2 test performance were 4.2 and 5.6 % , respectively . A correlation was observed ( P < 0.05 ) between  Yo – Yo IE2 test performance and the total ( r = 0.74 ) and high-intensity ( r = 0.58 ) running distance covered in a match . A correlation was also evident ( P < 0.01 ) between Yo – Yo IE2 test heart rate after 6 min expressed in percentage of maximal heart rate and the peak values for high-intensity running performed by midfielders in 5-min ( r = −0.71 ) , 15-min ( r = −0.75 ) and 45-min periods ( r = −0.77 ) . The present data demonstrate that the Yo – Yo IE2 test is reproducible and can be used to determine the capacity of elite soccer players to perform intense intermittent exercise . Furthermore , the Yo – Yo IE2 test was shown to be a sensitive tool that not only relates to match performance but can also differentiate between intermittent exercise performance of players in various st and ards , stages of the season and playing positions The study tested the hypothesis that long-term soccer training has positive impact on cardiovascular profile , body composition , bone health , and physical capacity in inactive , pre-menopausal women with mild hypertension . The study applied a r and omized controlled design in which physically inactive middle-aged women were separated into a soccer training group  ( n=19 ; SOC ) and a control group ( n=12 ; CON ) . SOC performed 128±29 ( ±SD ) one-h small-sided soccer training sessions over one year . Blood pressure , body composition , blood lipid profile , and fitness level were determined pre- and post-intervention . Over one year , mean arterial pressure decreased more in SOC than in CON ( -5±7 vs + 4±5 mmHg ; P<.05 ) . Total-body fat mass decreased more ( P<.05 ) in SOC than in CON ( -2.5±2.5 vs + 0.6±3.2 kg ; P<.05 ) , while the change scores for lean body mass were not significantly different in SOC ( 2.6±2.7 kg ) compared to CON ( 1.1±1.9 kg , P=.09 ) . Over one year , change scores in whole-body bone mineral density ( 0.004±0.032 vs -0.019±0.026 g·cm2 ) as well as bone mineral content ( 30±70 vs -39±113 g ) were positive in SOC compared to CON ( P<.05 ) . Post-intervention plasma triglycerides decreased more ( -0.1±0.7 vs + 0.2±0.2 mmol·L-1 ) and HDL cholesterol increased more ( 0.2±0.7 vs -0.2±0.2 mmol·L-1 ) in SOC than in CON ( P<.05 ) . Yo-Yo intermittent endurance level 1 ( 122±105 vs 2±21 % ) and 20-m sprint performance ( 6±6 vs -1±2 % ) increased more ( P<.05 ) in SOC than in CON . In conclusion , long-term soccer training result ed in broad-spectrum improvements in the health profile of untrained , pre-menopausal women with mild hypertension , including cardiovascular , metabolic , and musculo-skeletal benefits Abstract We aim ed to analyse the effects of combined strength and power training during the competitive season on physical fitness in high-level amateur football players . Sixteen male players ( 22.5 ( SD 2.5 ) years , 1.79 ( 0.05 ) m , 76.8 ( 6.1 ) kg ) from one team were r and omly assigned to either a strength training ( ST , N = 8) or a control ( CON , N = 8) group . ST conducted lower extremity resistance exercises combined with plyometrics and /or sprints 2 × 30 min per week for 7 weeks . CON performed technical-tactical training during the same time period . Before and after training several physical fitness parameters were assessed : one-repetition maximum ( 1-RM , half squat ) , isometric peak strength and rate of force development ( RFD , leg press ) , jump height ( countermovement , CMJ , drop jump , DJ ) , sprint times , agility , and intermittent endurance . Large significant test × group interactions were found for 1-RM , CMJ , and DJ reactivity index with increases in CT relative to CON(+11 to 18 % ) . Although not significant ( P < 0.20 ) , likely practically relevant effects were observed for isometric peak strength and RFD ( + 24 to 29 % ) . We found no relevant interaction effects for agility , sprint times , and intermittent endurance . A 7-week in-season combined strength and power training program can improve relevant strength and jump parameters in high-level amateur football players Abstract The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players . In a r and omised controlled trial 18 male sub-elite players were exposed to additional speed endurance production ( SEP ) or speed endurance maintenance ( SEM ) training ( two additional sessions/wk for 4 weeks ) during the competitive season . Players performed the Yo-Yo intermittent recovery level 2 test ( YYIR2 ) and a repeated sprint test ( RST ) pre- and post-intervention .  Yo-Yo IR2 performance increased ( p<0.001 ) by 50 ± 8 % and 26 ± 5 % in SEP and SE 
    Output:
    
Conclusions : Our analysis provides evidence that Yo-Yo intermittent tests reference values differ with respect to the type and level of sport performed .