***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 The purpose of this study was to determine if changes in triceps-surae tendon stiffness ( TST K ) could affect running economy ( RE ) in highly trained distance runners . The intent was to induce increased TST K in a subgroup of runners by an added isometric training program . If TST K is a primary determinant of RE , then the energy cost of running ( EC ) should decrease in the trained subjects . EC was measured via open-circuit spirometry in 12 highly trained male distance runners , and TST K was measured using ultrasonography and dynamometry . Runners were r and omly assigned to either a training or control group . The training group performed 4 × 20 s isometric contractions at 80 % of maximum voluntary plantarflexion moment three times per week for 8 weeks . All subjects ( mean $ $ \dot{V}{\text{O } } _ { 2 } { \max } $ $ = 67.4 ± 4.6 ml kg−1 min−1 ) continued their usual training for running . TST K was measured every 2 weeks . EC was measured in both training and control groups before and after the 8 weeks at three submaximal velocities , corresponding to 75 , 85 and 95 % of the speed at lactate threshold ( sLT ) . Isometric training did neither result in a mean increase in TST K ( 0.9 ± 25.8 % ) nor a mean improvement in RE ( 0.1 ± 3.6 % ) ; however , there was a significant relationship ( r2 = 0.43 , p = 0.02 ) between the change in TST K and change in EC , regardless of the assigned group . It was concluded that TST K and EC are somewhat labile and change together Berryman , N , Maurel , D , and Bosquet , L. Effect of plyometric vs. dynamic weight training on the energy cost of running . J Strength Cond Res 24(7 ) : 1818 - 1825 , 2010-The purpose of this study is to compare the effects of 2 strength training methods on the energy cost of running ( Cr ) .  Thirty-five moderately to well-trained male endurance runners were r and omly assigned to either a control group ( C ) or 2 intervention groups . All groups performed the same endurance-training program during an 8-week period . Intervention groups added a weekly strength training session design ed to improve neuromuscular qualities . Sessions were matched for volume and intensity using either plyometric training ( PT ) or purely concentric contractions with added weight ( dynamic weight training [ DWT ] ) . We found an interaction between time and group ( p < 0.05 ) and an effect of time ( p < 0.01 ) for Cr . Plyometric training induced a larger decrease of Cr ( 218 ± 16 to 203 ± 13 ml·kg−1·km−1 ) than DWT ( 207 ± 15 to 199 ± 12 ml·kg−1·km−1 ) , whereas it remained unchanged in C. Pre-post changes in Cr were correlated with initial Cr ( r = −0.57 , p < 0.05 ) . Peak vertical jump height ( VJHpeak ) increased significantly ( p < 0.01 ) for both experimental groups ( DWT = 33.4 ± 6.2 to 34.9 ± 6.1 cm , PT = 33.3 ± 4.0 to 35.3 ± 3.6 cm ) but not for C. All groups showed improvements ( p < 0.05 ) in Perf3000 ( C = 711 ± 107 to 690 ± 109 seconds , DWT = 755 ± 87 to 724 ± 77 seconds , PT = 748 ± 81 to 712 ± 76 seconds ) . Plyometric training were more effective than DWT in improving Cr in moderately to well-trained male endurance runners showing that athletes and coaches should include explosive strength training in their practice s with a particular attention on plyometric exercises . Future research is needed to establish the origin of this adaptation Abstract .Previous research has reported that plyometric training improves running economy ( RE ) and ultimately distance-running performance , although the exact mechanism by which this occurs remains unclear . This study examined whether changes in running performance result ing from plyometric training were related to alterations in lower leg musculotendinous stiffness ( MTS ) . Seventeen male runners were pre- and post-tested for lower leg MTS , maximum isometric force , rate of force development , 5-bound distance test ( 5BT ) , counter movement jump ( CMJ ) height , RE , V˙O2max , lactate threshold ( Thla ) , and 3-km time . Subjects were r and omly split into an experimental ( E ) group which completed 6 weeks of plyometric training in conjunction with their normal running training , and a control ( C ) group which trained as normal . Following the training period , the E group significantly improved 3-km performance ( 2.7 % ) and RE at each of the tested velocities , while no changes in V˙O2max or Thla were recorded . CMJ height , 5BT , and MTS also increased significantly . No significant changes were observed in any measures for the C group . The results clearly demonstrated that a 6-week plyometric programme led to improvements in 3-km running performance . It is postulated that the increase in MTS result ed in improved RE . We speculate that the improved RE led to changes in 3-km running performance , as there were no corresponding alterations in V˙O2max or Thla Purpose The purpose of the current study was to investigate the effects of adding strength training to normal endurance training on running performance and running economy in well-trained female athletes . We hypothesized that the added strength training would improve performance and running economy through altered stiffness of the muscle-tendon complex of leg extensors . Methods Nineteen female endurance athletes [ maximal oxygen consumption ( VO2max ) : 53±3 ml∙kg-1∙min-1 , 5.8 h weekly endurance training ] were r and omly assigned to either normal endurance training ( E , n = 8) or normal endurance training combined with strength training ( E+S , n = 11 ) . The strength training consisted of four leg exercises [ 3 x 4–10 repetition maximum ( RM ) ] , twice a week for 11 weeks . Muscle strength , 40 min all-out running distance , running performance determinants and patellar tendon stiffness were measured before and after the intervention . Results E+S increased 1RM in leg exercises ( 40 ± 15 % ) and maximal jumping height in counter movement jump ( 6 ± 6 % ) and squat jump ( 9 ± 7 % , p < 0.05 ) . This was accompanied by increased muscle fiber cross sectional area of both fiber type I ( 13 ± 7 % ) and fiber type II ( 31 ± 20 % ) in m. vastus lateralis ( p < 0.05 ) , with no change in capillary density in m. vastus lateralis or the stiffness of the patellar tendon . Neither E+S nor E changed running economy , fractional utilization of VO2max or VO2max . There were also no change in running distance during a 40 min all-out running test in neither of the groups . Conclusion Adding heavy strength training to endurance training did not affect 40 min all-out running performance or running economy compared to endurance training only PURPOSE It has been suggested that endurance training influences the running economy ( CR ) and the oxygen uptake ( .VO(2 ) ) kinetics in heavy exercise by accelerating the primary phase and attenuating the .VO(2 ) slow component . However , the effects of heavy weight training ( HWT ) in combination with endurance training remain unclear . The purpose of this study was to examine the influence of a concurrent HWT+endurance training on CR and the .VO(2 ) kinetics in endurance athletes . METHODS Fifteen triathletes were assigned to endurance+strength ( ES ) or endurance-only ( E ) training for 14 wk . The training program was similar , except ES performed two HWT sessions a week . Before and after the training period , the subjects performed 1 ) an incremental field running test for determination of .VO(2max ) and the velocity associated ( V(.VO2max ) ) , the second ventilatory threshold ( VT(2 ) ) ; 2 ) a 3000-m run at constant velocity , calculated to require 25 % of the difference between .VO(2max ) and VT(2 ) , to determine CR and the characteristics of the VO(2 ) kinetics ; 3 ) maximal hopping tests to determine maximal mechanical power and lower-limb stiffness ; 4 ) maximal concentric lower-limb strength measurements . RESULTS After the training period , maximal strength were increased ( P < 0.01 ) in ES but remained unchanged in E. Hopping power decreased in E ( P < 0.05 ) . After training , economy ( P < 0.05 ) and hopping power ( P < 0.001 ) were greater in ES than in E. .VO(2max ) , leg hopping stiffness and the .VO(2 ) kinetics were not significantly affected by training either in ES or E. CONCLUSION Additional HWT led to improved maximal strength and running economy with no significant effects on the .VO(2 ) kinetics pattern in heavy exercise 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 
    Output:
    
Resistance training led to general improvements in muscular strength , running economy , muscle power factors , and direct performance in distances between 1,500 and 10,000 m. Such improvements were not accompanied by a significant increase in body mass or signs of overtraining .
However , improvements did not occur in all cases , suggesting that they might depend on the specific characteristics of the resistance training applied .