***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: To investigate the effects of simultaneous explosive-strength and endurance training on physical performance characteristics , 10 experimental ( E ) and 8 control ( C ) endurance athletes trained for 9 wk . The total training volume was kept the same in both groups , but 32 % of training in E and 3 % in C was replaced by explosive-type strength training . A 5-km time trial ( 5 K ) , running economy ( RE ) , maximal 20-m speed ( V20 m ) , and 5-jump ( 5J ) tests were measured on a track . Maximal anaerobic ( MART ) and aerobic treadmill running tests were used to determine maximal velocity in the MART ( VMART ) and maximal oxygen uptake ( VO2 max ) . The 5 K time , RE , and VMART improved ( P < 0.05 ) in E , but no changes were observed in C. V20 m and 5J increased in E ( P < 0.01 ) and decreased in C ( P < 0.05 ) . VO2 max increased in C ( P < 0.05 ) , but no changes were observed in E. In the pooled data , the changes in the 5 K velocity during 9 wk of training correlated ( P < 0.05 ) with the changes in RE [ O2 uptake ( r = -0.54 ) ] and VMART ( r = 0.55 ) . In conclusion , the present simultaneous explosive-strength and endurance training improved the 5 K time in well-trained endurance athletes without changes in their VO2 max . This improvement was due to improved neuromuscular characteristics that were transferred into improved VMART and running economy Fifteen highly trained distance runners ( & OV0312;O2max 71.1 ± 6.0 ml·min−1·kg−1 , mean ± SD ) were r and omly assigned to a  plyometric training ( PLY ; n = 7 ) or control ( CON ; n = 8) group . In addition to their normal training , the PLY group undertook 3 × 30 minutes PLY sessions per week for 9 weeks . Running economy ( RE ) was assessed during 3 × 4 minute treadmill runs ( 14 , 16 , and 18 km·h−1 ) , followed by an incremental test to measure & OV0312;O2max . Muscle power characteristics were assessed on a portable , unidirectional ground reaction force plate . Compared with CON , PLY improved RE at 18 km·h−1 ( 4.1 % , p = 0.02 ) , but not at 14 or 16 km·h−1 . This was accompanied by trends for increased average power during a 5-jump plyometric test ( 15 % , p = 0.11 ) , a shorter time to reach maximal dynamic strength during a strength quality assessment test ( 14 % , p = 0.09 ) , and a lower & OV0312;O2-speed slope ( 14 % , p = 0.12 ) after 9 weeks of PLY . There were no significant differences in cardiorespiratory measures or & OV0312;O2max as a result of PLY . In a group of highly-trained distance runners , 9 weeks of PLY improved RE , with likely mechanisms residing in the muscle , or alternatively by improving running mechanics In this study , we investigated whether a heavy strength training program , as an additive to an endurance running program , would cause significant improvements in 3-km run time in a group of recreationally fit women when compared with endurance-only ( EO ) training . Sixteen women aged between 18 and 27 years of age were r and omly assigned to either an EO group ( n = 9 ) or a concurrent strength and endurance ( CSE ) group ( n = 7 ) . A 10-week training program for both groups consisted of an endurance running program performed three afternoons per week . The CSE group also participated in strength training on the morning of each running session . Testing was conducted pre and post training in a 3-km time trial and measured & OV0312;o2peak , running economy , muscular strength ( 1 repetition maximum ) , and body composition and girth . There was a trend ( P = 0.07 ) toward greater improvement in 3-km performance time for the CSE group ( 106.7 ± 91.4 seconds ) when compared with the EO group ( 77.3 ± 93.0 seconds ) . Further , the CSE group showed an increase in strength levels when compared with the EO group . The CSE group showed significant increases ( P ≤ 0.05 ) in the parallel squat and hamstring curl , and a significant increase ( P ≤ 0.05 ) was also found in upper body strength for the bench press ( 11.9 % increase ) when compared with the EO group . There were no significant differences between the two groups for & OV0312;o2peak , running economy , body composition , or girth measurements . This study found no negative or compatibility problems when heavy strength training was added to an endurance running program , and a nonsignificant increase in improvement for 3-km times was evident The purpose of this study was to examine the efficacy of 11 wk of resistance training to failure vs. nonfailure , followed by an identical 5-wk peaking period of maximal strength and power training for both groups as well as to examine the underlying physiological changes in basal circulating anabolic and catabolic hormones . Forty-two physically active men were matched and then r and omly assigned to either a training to failure ( RF ; n = 14 ) , nonfailure ( NRF ; n = 15 ) , or control groups ( C ; n = 13 ) . Muscular and power testing and blood draws to determine basal hormonal concentrations were conducted before the initiation of training ( T0 ) , after 6 wk of training ( T1 ) , after 11 wk of training ( T2 ) , and after 16 wk of training ( T3 ) . Both RF and NRF result ed in similar gains in 1-repetition maximum bench press ( 23 and 23 % ) and parallel squat ( 22 and 23 % ) , muscle power output of the arm ( 27 and 28 % ) and leg extensor muscles ( 26 and 29 % ) , and maximal number of repetitions performed during parallel squat ( 66 and 69 % ) . RF group experienced larger gains in the maximal number of repetitions performed during the bench press . The peaking phase ( T2 to T3 ) after NRF result ed in larger gains in muscle power output of the lower extremities , whereas after RF it result ed in larger gains in the maximal number of repetitions performed during the bench press . Strength training leading to RF result ed in reductions in resting concentrations of IGF-1 and elevations in IGFBP-3 , whereas NRF result ed in reduced resting cortisol concentrations and an elevation in resting serum total testosterone concentration . This investigation demonstrated a potential beneficial stimulus of NRF for improving strength and power , especially during the subsequent peaking training period , whereas performing sets to failure result ed in greater gains in local muscular endurance . Elevation in IGFBP-3 after resistance training may have been compensatory to accommo date the reduction in IGF-1 to preserve IGF availability Abstract Ramírez-Campillo , R , Álvarez , C , Henríquez-Olguín , C , Baez , EB , Martínez , C , And rade , DC , and Izquierdo , M. Effects of plyometric training on endurance and explosive strength performance in competitive middle- and long-distance runners . J Strength Cond Res 28(1 ) : 97–104 , 2014—The purpose of this study was to examine the effect of a short-term plyometric training program on explosive strength and endurance performance in highly competitive middle- and long-distance runners . Athletes were r and omly assigned to a  control group ( CG , n = 18 , 12 men ) and an  explosive strength training group ( TG , n = 18 , 10 men ) .  Drop jump ( DJ ) from 20 ( DJ20 ) and 40 cm ( DJ40 ) , countermovement jump with arms ( CMJA ) , 20-m sprint time , and 2.4-km endurance run time test were carried out before and after 6 weeks of explosive strength training . Also , the combined st and ardized performance ( CSP ) in the endurance and explosive strength test was analyzed . After intervention , the CG did not show any significant change in performance , whereas the TG showed a significant reduction in 2.4-km endurance run time ( −3.9 % ) and 20-m sprint time ( −2.3 % ) and an increase in CMJA ( + 8.9 % ) , DJ20 ( + 12.7 % ) , and DJ40 ( 16.7 % ) explosive performance . Strength training group also exhibited a significant increase in CSP , although the CG showed significant reduction . We conclude that properly programmed concurrent explosive strength and endurance training could be advantageous for middle- and long-distance runners in their competitive performance , especially in events characterized by sprinting actions with small time differences at the end of the race Sáez Sáez de villarreal , E , Izquierdo , M , and Gonzalez-Badillo , JJ . Enhancing jump performance after combined vs. maximal power , heavy-resistance , and plyometric training alone . J Strength Cond Res 25(12 ) : 3274–3281 , 2011—The purpose of this study was to examine the effects of 5 different stimuli on jumping ability and power production after 7 weeks of training . Sixty-five ( 47 men and 18 women ) physical education students were r and omly assigned to 5 experimental groups that performed : combination of all training methods ( A ) ; heavy-resistance training using full-squat exercise ( i.e. , 56–85 % of 1 RM for 3–6 repetitions ) ( B ) ; power-oriented strength training using a parallel-squat exercise ( i.e. , 100–130 % of load that maximizes power output for 2–6 repetitions ) ( C ) ; power-oriented strength training using a loaded countermovement jumping ( i.e. , 70–100 % of load that maximizes power output for 2–5 repetitions ; countermovement jump [ CMJ ] ) ( D ) ; and plyometric jumping ( E ) . The CMJ ( cm ) , loaded CMJ ( cm ) , maximum rate of force development ( RFDmax ) during early concentric phase of loaded CMJ ( N·s−1 ) and power output during early concentric phase of loaded CMJ ( watts ) were measured before and after 7 weeks of training . Significant improvements in CMJ ( from 7.8 to 13.2 % ) were observed in all groups . Significantly greater increases in power output during loaded jumps were observed in A ( 10–13 % ) and D ( 8–12 % ) groups compared with in the other groups . Significant increases in RFDmax were observed in A ( 20–30 % ) , C ( 18–26 % ) , and D ( 20–26 % ) groups . The results of this study provide evidence to suggest that if training program is design ed and implemented correctly , both traditional slow velocity training and faster power-oriented strength training alone , or in combination with plyometric training , would provide a positive training stimulus to enhance jumping performance The purpose of this study was to examine the effect of 3 volumes of heavy resistance , average relative training intensity ( expressed as a percentage of 1 repetition maximum that represented the absolute kilograms lifted divided by the number of repetitions performed ) programs on maximal strength ( 1RM ) in Snatch ( Sn ) , Clean & Jerk ( C&J ) , and Squat ( Sq ) . Twenty-nine experienced ( .3 years ) , trained junior weight-lifters were r and omly assigned into 1 of 3 groups : low-intensity group ( LIG ; n = 12 ) , moderate-intensity group ( MIG ; n = 9 ) , and high-intensity group ( HIG ; n = 8) . All subjects trained for 10 weeks , 4–5 days a week , in a periodized routine using the same exercises and training volume ( expressed as total number of repetitions performed at intensities equal to or greater than 60 % of 1RM ) , but different programmed total repetitions at intensities of .90–100 % of 1RM for the entire 10-week period : LIG ( 46 repetitions ) , MIG ( 93 repetitions ) , and HIG ( 184 repetitions ) . During the training period , MIG and LIG showed a significant increase ( p < 0.01–0.05 ) for C & J ( 10.5 % and 3 % for MIG and LIG , respectively ) and Sq ( 9.5 % and 5.3 % for MIG and LIG , respectively ) , whereas in HIG the increase took place only in Sq ( 6.9 % , p < 0.05 ) . A calculation of effect sizes revealed greater strength gains in the MIG than in HIG or LIG . There were no significant differences between LIG and HIG training volume-induced strength gains . All the subjects in HIG were unable to fully accomplish the repetitions programmed at relative intensities greater than 90 % of 1RM . The present results indicate that short-term resistance training using moderate volumes of high relative intensity tended to produce higher enhancements in weightlifting performance compared with low and high volumes of high relative training intensities of equal total volume in experienced , trained young weightlifters . Therefore , for the present population of weightlifters , it may be beneficial to use the MIG training protocol to improve the weightlifting program at least in a short-term ( 10 weeks ) cycle of training The present study examines changes in muscle structure and neuromuscular performance induced by 15 weeks of power training with explosive muscle actions . Twenty-three subjects , including 10 controls , volunteered for the study .  Muscle biopsies were obtained from the gastrocnemius muscle before and after the training period , while maximal voluntary isometric contractions ( MVC ) and drop jump tests were performed once every 
    Output:
    
In conclusion , a strength training program including low to high intensity resistance exercises and plyometric exercises performed 2 - 3 times per week for 8 - 12 weeks is an appropriate strategy to improve RE in highly trained middle- and long-distance runners