human
***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: The purpose of this study was to determine if explosive upper-body performance could be improved when it was preceded by conditioning contraction protocol s that incorporate resistance exercise . Providing that performance was enhanced , it was also the intention to determine the optimal conditioning contraction load for enhancing performance . Eight recreationally trained men completed 4 experimental sessions . Each session consisted of a warm-up , 3 bench press throws ( pre ) , a conditioning protocol , and 3 bench press throws ( post ) . The different conditioning protocol s consisted of 5 bench press repetitions using 100 , 75 , or 50 % of 5 repetition maximum ( 5RM ) strength . The fourth protocol , in which no repetitions were completed , acted as a control . Participants performed each conditioning protocol on a different day , and the order in which the protocol s were performed was r and omized . Average power , assessed during the bench press throws , was determined for the starting segment and the end segment ( point of bar release ) for each throw . Comparisons in average power , for each segment of the bench press 1RM , were made between the pre- and postconditioning protocol bench press throws . None of the conditioning protocol s had an effect on bench press throw performance in either of the 2 segments of the movement . The results suggest there is no performance advantage when explosive upper-body movement is preceded by resistance exercise of varying loads . Alternatively , the performance of a set of resistance exercise did not compromise explosive upper-body performance . Considering this , training methods that combine both resistance exercise and plyometric-like exercise may offer a practical and time-efficient training system PURPOSE To test whether active and passive warm-up conducted before eccentric exercise attenuates clinical markers of muscle damage . METHODS Untrained subjects were exposed to one of five conditions : low-heat passive warm-up ( N = 10 ) , high-heat passive warm-up ( N = 4 ) , or active warm-up ( N = 9 ) , preceding eccentric exercise ; eccentric exercise without warm-up ( N = 10 ) ; or high-heat passive warm-up without eccentric exercise ( N = 10 ) . Passive warm-up of the elbow flexors was achieved using pulsed short-wave diathermy , and active warm-up was achieved by concentric contraction . Creatine kinase ( CK ) activity , strength , range of motion , swelling , and muscle soreness were observed before treatment ( baseline ) and 24 , 48 , 72 , and 168 h after treatment . RESULTS High-heat passive warm-up without eccentric exercise did not affect any marker of muscle damage and was used as our control group . Markers of muscle damage were not different between groups that did or did not conduct warm-up before eccentric exercise . The active warm-up and eccentric groups exhibited a greater circumferential increase than controls ( P < 0.0002 ) , however , that was not observed after passive warm-up . Additionally , the active warm-up group exhibited a greater CK response than controls at 72 h ( P < 0.05 ) . The high-heat passive warm-up before eccentric exercise group exhibited significant change from controls at the least number of time points , but due to a small sample size ( N = 4 ) , these data should be viewed as preliminary . CONCLUSION Our observations suggest that passive warm-up performed before eccentric exercise may be more beneficial than active warm-up or no warm-up in attenuating swelling but does not prevent , attenuate , or resolve more quickly the other clinical symptoms of eccentric muscle damage as produced in this study OBJECTIVE : We tested the hypothesis that altering the pre-exercise muscle temperature would influence the magnitude of muscle damage induced by eccentric exercise . SUBJECTS : Female students who had no experience in resistance training were placed into either a  microwave treatment group ( n = 10 ) or an icing treatment group ( n = 10 ) . DESIGN AND SETTING : Subjects in each group performed 12 maximal eccentric actions of the forearm flexors of each arm on 2 separate occasions separated by 4 weeks . Before testing , the exercise arm was subjected to either passive warming ( microwave ) or control for the microwave treatment group or cooling ( icing ) or control for the icing treatment group . The control arm performed the same exercise protocol without treatment . Limbs were r and omized for treatment or control and order of testing . Deep muscle temperature increased by approximately 3 degrees C after the microwave treatment and decreased approximately 5 degrees C after the icing treatment . MEASUREMENTS : We evaluated changes in maximal isometric force and indirect markers of muscle damage , including range of motion , upper arm circumference , muscle soreness , and plasma creatine kinase activity , in the microwave and control and icing and control groups using a 2-way , repeated- measures analysis of variance . RESULTS : All measures changed significantly ( P < .01 ) after exercise , but neither of the treatments demonstrated significant effects on most of the variables compared with the control . CONCLUSIONS : These results suggest that pre-exercise cooling does not affect the magnitude of muscle damage in response to eccentric exercise . Similarly , pre-exercise passive muscle warming did not prove beneficial in attenuating indicators of muscle damage . Thus , any beneficial effects of warm-up exercise can not be attributed to the effects of increased muscle temperature PURPOSE The purpose of this study was to investigate the influence of warm-up ( WU ) intensity on supramaximal kayak ergometer performance . METHODS In the initial testing session , eight institute of sport kayak squad members performed a grade d exercise test  for determination of VO2max and lactate ( La ) parameters . In a r and om , counterbalanced order , subjects subsequently performed WU for 15-min at either their aerobic threshold ( W1 ) , their anaerobic threshold ( W3 ) , or mid-way between their aerobic threshold and anaerobic threshold ( W2 ) . A 5-min passive rest period and then a 2-min , all-out kayak ergometer test followed the WU . RESULTS For the three different WU conditions , no significant differences were observed for average power , peak VO2 , total VO2 , total VCO2 , or accumulated oxygen deficit ( AOD ) during the 2-min test . However , when compared with W3 , differences in average power approached significance after both W1 ( P = 0.09 ) and W2 ( P = 0.10 ) . Furthermore , when compared with W3 , average power during the first half of the 2-min test was significantly greater after W2 ( P < 0.05 ) and approached significance after W1 ( P = 0.06 ) . After each WU period , there was a significant difference in blood pH ( W1>W2>W3 ; P < 0.05 ) and blood [ La ] ( W1<W2<W3 ; P < 0.05 ) . Despite the significantly different metabolic acidemia after each WU condition , there were no significant differences in the VO2 responses to the 2-min test . However , the greater metabolic acidemia after W3 was associated with impaired 2-min kayak ergometer performance . CONCLUSIONS It was concluded , that although a degree of metabolic acidemia may be necessary to speed O2 kinetics , if the WU is too intense , the associated metabolic acidemia may impair supramaximal performance by reducing the anaerobic energy contribution and /or interfering with muscle contractile processes The effects of increased muscle temperature via continuous ultrasound prior to a maximal bout of eccentric exercise were investigated on the symptoms of  delayed onset muscle soreness ( DOMS ) of the elbow flexors .  Perceived muscle soreness , upper arm circumferences , range of motion ( ROM ) , and isometric and isokinetic strength were measured over 7 days on 14 college-aged men ( n = 6 ) and women ( n = 8) . Ten minutes of continuous ultrasound ( ULT ) or sham-ultrasound ( CON ) were administered . Muscle temperature was measured in the biceps brachii of both arms . Muscle temperature increased by 1.79 ° ± 0.49 ° C ( mean ± SD ) in the experimental arm of the ULT group . Muscle soreness was induced by a single bout of 50 maximal eccentric contractions . The ULT group did not differ significantly ( p < 0.05 ) from the CON group with respect to perceived muscle soreness , upper arm circumference , ROM , and isometric and isokinetic strength . In conclusion , increased muscle temperature failed to provide significant prophylactic effects on the symptoms of DOMS This study investigated whether a fatiguing concentric exercise performed immediately before eccentric exercise would exacerbate eccentric exercise-induced muscle damage .  One arm of nine female subjects ( mean + /- s : 23.3 + /- 6.7 years ) performed 12 maximal eccentric actions of the elbow flexors ( ECC ) , and the other arm performed 100 repetitions of isokinetic concentric actions of the elbow flexors followed by the same eccentric exercise ( CON-ECC ) . The two exercise regimens ( ECC and CON-ECC ) were separated by 2 weeks and presented in a counterbalanced order . Changes in muscle soreness level , maximal isometric force generation , relaxed and flexed elbow joint angle , upper arm circumference and plasma creatine kinase activity were compared between the ECC and CON-ECC conditions . All measures changed significantly after both ECC and CON-ECC ; however , there were significant differences in the changes between the conditions . A lower level of soreness , a faster recovery of maximal isometric force generation , a smaller decrease in relaxed elbow joint angle and a smaller increase in upper arm circumference and creatine kinase activity were evident after the CON-ECC condition compared to the ECC condition . Thus , it would seem that muscle damage was attenuated by performance of previous concentric exercise . An additional experiment using a different group of subjects ( n = 5 ) showed that warm-up exercise before the eccentric exercise also attenuated eccentric exercise-induced muscle damage Abstract The aim of this study was to examine the effect of concentric warm-up exercise on eccentrically induced changes in muscle strength , range of motion , and soreness  of the elbow flexors . Ten resistance-exercise naïve participants performed  intermittent incremental eccentric actions ( 42 in total ) of the elbow flexor muscles of each arm to induce muscle damage . The arms of each participant were r and omly assigned either to a pre-eccentric exercise warm-up involving intermittent concentric exercise ( warm-up ) or no prior exercise ( control ) .  Strength , range of motion , and ratings of soreness were recorded before and 1 , 2 , 3 , 4 , and 7 days after exercise . Strength , range of motion , and soreness during muscular movements changed over time ( P at most 0.01 ; Cohen 's d at least 0.51 , medium ) . There was an interaction ( P < 0.001 ) for strength , showing a smaller reduction after exercise for warm-up than control ( P < 0.001 , d = 2.44 , large effect ) . The decreased range of motion was less for warm-up than control for the arm while extended ( P < 0.001 ) , flexed ( P = 0.002 ) , and relaxed ( P = 0.004 ) . Muscle soreness was reduced for the warm-up group , while the muscle was flexed , extended , and relaxed compared with control ( P < 0.001 ) . The results demonstrate that a concentric warm-up exercise attenuates the reduction in loss of strength , range of motion , and muscle soreness after eccentric-exercise-induced muscle damage and might allow higher intensities of training to be performed & NA ; Knudson , D.V. , G.J. Noffal , R.E. Bahamonde , J.A. Bauer , and J.R. Blackwell . Stretching has no effect on tennis serve performance . J. Strength Cond . Res . 18(3):654–656 . 2004.—Stretching prior to vigorous physical activity has been shown to decrease high‐force muscular performance , but little is known about the effect of stretching on speed and accuracy movements . Serving percentage and radar measurements of ball speed were studied to examine the acute effect of stretching on tennis serve performance . Eighty‐three tennis players from beginning level to advanced volunteered to serve following traditional ( T ) warm‐up and traditional plus stretching ( S ) conditions .  Service speeds and service percentage of each condition were measured . Dependent t‐tests showed nonsignificant effects of stretching  on service speed ( p = 0.06 ) or accuracy ( p = 0.35 ) , and this lack of an effect was similar for all skill levels , age , and gender . The large sample and good statistical power in this study indicated that these observations are not likely type II errors . There was no short‐term effect  of stretching in the warmup on the tennis serve performance of adult players , so adding stretching to the traditional 5‐minute warm‐up in tennis does not affect serve performance The purpose of this study was to compare the acute effects of static stretching ; dynamic exercises and high volume upper extremity plyometric activity on tennis serve performance . Twenty-six elite young tennis players ( 15.1 ± 4.2 years , 167.9 ± 5.8 cm and 61.6 ± 8.1 kg ) performed 4 different warm-up ( WU ) routines in a r and om order on non-consecutive days . The WU methods consisted of traditional WU ( jogging , rally and serve practice ) ( TRAD ) ; traditional WU and static stretching ( TRSS ) ; traditional WU and dynamic exercise ( TRDE ) ; and traditional WU and high volume upper extremity plyometric activity ( TRPLYP ) . Following each WU session , subjects were tested on a tennis serve ball speed test . TRAD , TRSS , TRDE and TRPLYO were compared by repeated measurement analyses of variance and post-hoc comparisons . In this study a 1 to 3 percent increase in tennis serve ball speed was recorded in TRDE and TRPLYO when compared to TRAD ( p < 0.05 ) . However , no significant change in ball speed performance between TRSS and TRAD . ( p > 0.05 ) . ICCs for ball speed showed strong reliability 
    Output:
    
agent
***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: The purpose of this study was to determine if explosive upper-body performance could be improved when it was preceded by conditioning contraction protocol s that incorporate resistance exercise . Providing that performance was enhanced , it was also the intention to determine the optimal conditioning contraction load for enhancing performance . Eight recreationally trained men completed 4 experimental sessions . Each session consisted of a warm-up , 3 bench press throws ( pre ) , a conditioning protocol , and 3 bench press throws ( post ) . The different conditioning protocol s consisted of 5 bench press repetitions using 100 , 75 , or 50 % of 5 repetition maximum ( 5RM ) strength . The fourth protocol , in which no repetitions were completed , acted as a control . Participants performed each conditioning protocol on a different day , and the order in which the protocol s were performed was r and omized . Average power , assessed during the bench press throws , was determined for the starting segment and the end segment ( point of bar release ) for each throw . Comparisons in average power , for each segment of the bench press 1RM , were made between the pre- and postconditioning protocol bench press throws . None of the conditioning protocol s had an effect on bench press throw performance in either of the 2 segments of the movement . The results suggest there is no performance advantage when explosive upper-body movement is preceded by resistance exercise of varying loads . Alternatively , the performance of a set of resistance exercise did not compromise explosive upper-body performance . Considering this , training methods that combine both resistance exercise and plyometric-like exercise may offer a practical and time-efficient training system PURPOSE To test whether active and passive warm-up conducted before eccentric exercise attenuates clinical markers of muscle damage . METHODS Untrained subjects were exposed to one of five conditions : low-heat passive warm-up ( N = 10 ) , high-heat passive warm-up ( N = 4 ) , or active warm-up ( N = 9 ) , preceding eccentric exercise ; eccentric exercise without warm-up ( N = 10 ) ; or high-heat passive warm-up without eccentric exercise ( N = 10 ) . Passive warm-up of the elbow flexors was achieved using pulsed short-wave diathermy , and active warm-up was achieved by concentric contraction . Creatine kinase ( CK ) activity , strength , range of motion , swelling , and muscle soreness were observed before treatment ( baseline ) and 24 , 48 , 72 , and 168 h after treatment . RESULTS High-heat passive warm-up without eccentric exercise did not affect any marker of muscle damage and was used as our control group . Markers of muscle damage were not different between groups that did or did not conduct warm-up before eccentric exercise . The active warm-up and eccentric groups exhibited a greater circumferential increase than controls ( P < 0.0002 ) , however , that was not observed after passive warm-up . Additionally , the active warm-up group exhibited a greater CK response than controls at 72 h ( P < 0.05 ) . The high-heat passive warm-up before eccentric exercise group exhibited significant change from controls at the least number of time points , but due to a small sample size ( N = 4 ) , these data should be viewed as preliminary . CONCLUSION Our observations suggest that passive warm-up performed before eccentric exercise may be more beneficial than active warm-up or no warm-up in attenuating swelling but does not prevent , attenuate , or resolve more quickly the other clinical symptoms of eccentric muscle damage as produced in this study OBJECTIVE : We tested the hypothesis that altering the pre-exercise muscle temperature would influence the magnitude of muscle damage induced by eccentric exercise . SUBJECTS : Female students who had no experience in resistance training were placed into either a  microwave treatment group ( n = 10 ) or an icing treatment group ( n = 10 ) . DESIGN AND SETTING : Subjects in each group performed 12 maximal eccentric actions of the forearm flexors of each arm on 2 separate occasions separated by 4 weeks . Before testing , the exercise arm was subjected to either passive warming ( microwave ) or control for the microwave treatment group or cooling ( icing ) or control for the icing treatment group . The control arm performed the same exercise protocol without treatment . Limbs were r and omized for treatment or control and order of testing . Deep muscle temperature increased by approximately 3 degrees C after the microwave treatment and decreased approximately 5 degrees C after the icing treatment . MEASUREMENTS : We evaluated changes in maximal isometric force and indirect markers of muscle damage , including range of motion , upper arm circumference , muscle soreness , and plasma creatine kinase activity , in the microwave and control and icing and control groups using a 2-way , repeated- measures analysis of variance . RESULTS : All measures changed significantly ( P < .01 ) after exercise , but neither of the treatments demonstrated significant effects on most of the variables compared with the control . CONCLUSIONS : These results suggest that pre-exercise cooling does not affect the magnitude of muscle damage in response to eccentric exercise . Similarly , pre-exercise passive muscle warming did not prove beneficial in attenuating indicators of muscle damage . Thus , any beneficial effects of warm-up exercise can not be attributed to the effects of increased muscle temperature PURPOSE The purpose of this study was to investigate the influence of warm-up ( WU ) intensity on supramaximal kayak ergometer performance . METHODS In the initial testing session , eight institute of sport kayak squad members performed a grade d exercise test  for determination of VO2max and lactate ( La ) parameters . In a r and om , counterbalanced order , subjects subsequently performed WU for 15-min at either their aerobic threshold ( W1 ) , their anaerobic threshold ( W3 ) , or mid-way between their aerobic threshold and anaerobic threshold ( W2 ) . A 5-min passive rest period and then a 2-min , all-out kayak ergometer test followed the WU . RESULTS For the three different WU conditions , no significant differences were observed for average power , peak VO2 , total VO2 , total VCO2 , or accumulated oxygen deficit ( AOD ) during the 2-min test . However , when compared with W3 , differences in average power approached significance after both W1 ( P = 0.09 ) and W2 ( P = 0.10 ) . Furthermore , when compared with W3 , average power during the first half of the 2-min test was significantly greater after W2 ( P < 0.05 ) and approached significance after W1 ( P = 0.06 ) . After each WU period , there was a significant difference in blood pH ( W1>W2>W3 ; P < 0.05 ) and blood [ La ] ( W1<W2<W3 ; P < 0.05 ) . Despite the significantly different metabolic acidemia after each WU condition , there were no significant differences in the VO2 responses to the 2-min test . However , the greater metabolic acidemia after W3 was associated with impaired 2-min kayak ergometer performance . CONCLUSIONS It was concluded , that although a degree of metabolic acidemia may be necessary to speed O2 kinetics , if the WU is too intense , the associated metabolic acidemia may impair supramaximal performance by reducing the anaerobic energy contribution and /or interfering with muscle contractile processes The effects of increased muscle temperature via continuous ultrasound prior to a maximal bout of eccentric exercise were investigated on the symptoms of  delayed onset muscle soreness ( DOMS ) of the elbow flexors .  Perceived muscle soreness , upper arm circumferences , range of motion ( ROM ) , and isometric and isokinetic strength were measured over 7 days on 14 college-aged men ( n = 6 ) and women ( n = 8) . Ten minutes of continuous ultrasound ( ULT ) or sham-ultrasound ( CON ) were administered . Muscle temperature was measured in the biceps brachii of both arms . Muscle temperature increased by 1.79 ° ± 0.49 ° C ( mean ± SD ) in the experimental arm of the ULT group . Muscle soreness was induced by a single bout of 50 maximal eccentric contractions . The ULT group did not differ significantly ( p < 0.05 ) from the CON group with respect to perceived muscle soreness , upper arm circumference , ROM , and isometric and isokinetic strength . In conclusion , increased muscle temperature failed to provide significant prophylactic effects on the symptoms of DOMS This study investigated whether a fatiguing concentric exercise performed immediately before eccentric exercise would exacerbate eccentric exercise-induced muscle damage .  One arm of nine female subjects ( mean + /- s : 23.3 + /- 6.7 years ) performed 12 maximal eccentric actions of the elbow flexors ( ECC ) , and the other arm performed 100 repetitions of isokinetic concentric actions of the elbow flexors followed by the same eccentric exercise ( CON-ECC ) . The two exercise regimens ( ECC and CON-ECC ) were separated by 2 weeks and presented in a counterbalanced order . Changes in muscle soreness level , maximal isometric force generation , relaxed and flexed elbow joint angle , upper arm circumference and plasma creatine kinase activity were compared between the ECC and CON-ECC conditions . All measures changed significantly after both ECC and CON-ECC ; however , there were significant differences in the changes between the conditions . A lower level of soreness , a faster recovery of maximal isometric force generation , a smaller decrease in relaxed elbow joint angle and a smaller increase in upper arm circumference and creatine kinase activity were evident after the CON-ECC condition compared to the ECC condition . Thus , it would seem that muscle damage was attenuated by performance of previous concentric exercise . An additional experiment using a different group of subjects ( n = 5 ) showed that warm-up exercise before the eccentric exercise also attenuated eccentric exercise-induced muscle damage Abstract The aim of this study was to examine the effect of concentric warm-up exercise on eccentrically induced changes in muscle strength , range of motion , and soreness  of the elbow flexors . Ten resistance-exercise naïve participants performed  intermittent incremental eccentric actions ( 42 in total ) of the elbow flexor muscles of each arm to induce muscle damage . The arms of each participant were r and omly assigned either to a pre-eccentric exercise warm-up involving intermittent concentric exercise ( warm-up ) or no prior exercise ( control ) .  Strength , range of motion , and ratings of soreness were recorded before and 1 , 2 , 3 , 4 , and 7 days after exercise . Strength , range of motion , and soreness during muscular movements changed over time ( P at most 0.01 ; Cohen 's d at least 0.51 , medium ) . There was an interaction ( P < 0.001 ) for strength , showing a smaller reduction after exercise for warm-up than control ( P < 0.001 , d = 2.44 , large effect ) . The decreased range of motion was less for warm-up than control for the arm while extended ( P < 0.001 ) , flexed ( P = 0.002 ) , and relaxed ( P = 0.004 ) . Muscle soreness was reduced for the warm-up group , while the muscle was flexed , extended , and relaxed compared with control ( P < 0.001 ) . The results demonstrate that a concentric warm-up exercise attenuates the reduction in loss of strength , range of motion , and muscle soreness after eccentric-exercise-induced muscle damage and might allow higher intensities of training to be performed & NA ; Knudson , D.V. , G.J. Noffal , R.E. Bahamonde , J.A. Bauer , and J.R. Blackwell . Stretching has no effect on tennis serve performance . J. Strength Cond . Res . 18(3):654–656 . 2004.—Stretching prior to vigorous physical activity has been shown to decrease high‐force muscular performance , but little is known about the effect of stretching on speed and accuracy movements . Serving percentage and radar measurements of ball speed were studied to examine the acute effect of stretching on tennis serve performance . Eighty‐three tennis players from beginning level to advanced volunteered to serve following traditional ( T ) warm‐up and traditional plus stretching ( S ) conditions .  Service speeds and service percentage of each condition were measured . Dependent t‐tests showed nonsignificant effects of stretching  on service speed ( p = 0.06 ) or accuracy ( p = 0.35 ) , and this lack of an effect was similar for all skill levels , age , and gender . The large sample and good statistical power in this study indicated that these observations are not likely type II errors . There was no short‐term effect  of stretching in the warmup on the tennis serve performance of adult players , so adding stretching to the traditional 5‐minute warm‐up in tennis does not affect serve performance The purpose of this study was to compare the acute effects of static stretching ; dynamic exercises and high volume upper extremity plyometric activity on tennis serve performance . Twenty-six elite young tennis players ( 15.1 ± 4.2 years , 167.9 ± 5.8 cm and 61.6 ± 8.1 kg ) performed 4 different warm-up ( WU ) routines in a r and om order on non-consecutive days . The WU methods consisted of traditional WU ( jogging , rally and serve practice ) ( TRAD ) ; traditional WU and static stretching ( TRSS ) ; traditional WU and dynamic exercise ( TRDE ) ; and traditional WU and high volume upper extremity plyometric activity ( TRPLYP ) . Following each WU session , subjects were tested on a tennis serve ball speed test . TRAD , TRSS , TRDE and TRPLYO were compared by repeated measurement analyses of variance and post-hoc comparisons . In this study a 1 to 3 percent increase in tennis serve ball speed was recorded in TRDE and TRPLYO when compared to TRAD ( p < 0.05 ) . However , no significant change in ball speed performance between TRSS and TRAD . ( p > 0.05 ) . ICCs for ball speed showed strong reliability 
    Output:
    