***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: Investigators have reported improved endurance performance and attenuated post- exercise muscle damage with carbohydrate-protein beverages ( CHO+P ) versus carbohydrate-only beverages ( CHO ) . However , these benefits have been demonstrated only when CHO+P was administered in beverage-form , and exclusively in male subjects . Thus , the purpose s of this study were to determine if an oral CHO+P gel  improved endurance performance and post-exercise muscle damage compared to a CHO gel , and determine if responses were similar between genders . Thirteen cyclists ( 8 men , 5 women ; & OV0312;O2peak = 57.9 ± 7.0 ml·kg-1·min-1 ) completed two timed cycle-trials to volitional exhaustion at 75 % of & OV0312;O2peak . At 15-minute intervals throughout these rides , subjects received CHO or CHO+P gels , which were matched for carbohydrate content ( CHO = 0.15 g CHO·kg BW-1 ; CHO+P = 0.15 g CHO + 0.038 g protein·kg BW-1 ) . Trials were performed using a r and omly counterbalanced , double-blind design . Subjects rode 13 % longer ( p > 0.05 ) when utilizing the CHO+P gel ( 116.6 ± 28.5 minutes ) versus the CHO gel ( 102.8 ± 25.0 minutes ) . In addition , men ( 101.8 ± 24.6 ; 114.8 ± 26.2 ) and women ( 104.4 ± 28.6 ; 119.6 ± 34.9 ) responded similarly to the CHO and CHO+P trials , with no significant treatment-by-gender effect . Postexercise creatine kinease ( CK ) was not significantly different between treatments . However , CK increased significantly following exercise in the CHO trial ( 183 ± 116 ; 267 ± 214 U·L-1 ) , but not the CHO+P trial ( 180 ± 133 ; 222 ± 141 U·L-1 ) . Therefore , to prolong endurance performance and prevent increases in muscle damage , it is recommended that male and female cyclists  consume CHO+P gels rather than CHO gels during and immediately following exercise UNLABELLED Both time-to-exhaustion ( TTE ) and time-trial ( TT ) exercise tests are commonly used to assess exercise performance , but no study has directly examined the reliability of comparable tests in the same subjects . PURPOSE To evaluate the reliability of comparable TTE and TT treadmill running tests of high and moderately high exercise intensity in endurance-trained male distance runners , and to vali date Hinckson and Hopkins TT prediction methods using log-log modeling from TTE results . METHODS After familiarization tests , eight endurance-trained male distance runners performed , in a r and omized , counterbalanced order , eight trials consisting of two 5-km TT and two 1500-m TT , and four TTE tests run at a speed equivalent to the average speed attained during both the 5-km and 1500-m TT distances . RESULTS Typical error of the estimate ( TEE ) expressed as a coefficient of variation for the 5-km TT , 5-km TTE , 1500-m TT , and 1500-m TTE were 2.0 , 15.1 , 3.3 , and 13.2 % , respectively . The st and ard error of the estimate for predicted TT running speed using log-log modeling from TTE results was 0.67 % , and the predicted versus criterion reliability of this method revealed TEE values of 1.6 % and 2.5 % for the prediction of 5-km and 1500-m TT , respectively . CONCLUSION The variability of 5-km and 1500-m TT tests was significantly less than for similar TTE treadmill protocol s. Despite the greater variability of the TTE tests , log-log modeling using the TTE test results reliably predicted actual TT performance PURPOSE Fourteen male cyclists were studied to compare the effect of carbohydrate-protein-antioxidant beverage ( CHOPA ) to an isocaloric carbohydrate-only ( CHO ) beverage on time to fatigue and muscle damage . METHODS Subjects performed two sets of rides to exhaustion on a cycle ergometer . In each set , the first ride was performed at 70 % VO2peak , and the second was performed 24 h later at 80 % . CHO or CHOPA was consumed every 15 min during exercise and immediately afterward . Plasma CK and LDH and muscle soreness were measured pre- and postexercise . RESULTS Time to fatigue was not different between CHO and CHOPA at 70 % VO2peak ( 95.8 + /- 29.7 vs 98.1 + /- 28.7 min ) , 80 % VO2peak ( 42.3 + /- 18.6 vs 42.9 + /- 21.8 min ) , or total performance time ( 138.1 + /- 39.3 vs 140.9 + /- 43.7 min ) . Postexercise CK was increased ( P < 0.05 ) from baseline in CHO ( 203 + /- 120 vs 582 + /- 475 U.L(-1 ) ) but not with CHOPA ( 188 + /- 119 vs 273 + /- 169 U.L(-1 ) ) . Similarly , LDH values increased over baseline in CHO ( 437 + /- 46 vs 495 + /- 64 U.L(-1 ) ) but not with CHOPA ( 432 + /- 40 vs 451 + /- 43 U.L(-1 ) ) . Postexercise CPK and LDH were higher after the CHO trial than after the CHOPA trial . Median postexercise muscle soreness was higher in CHO ( 3.0 + /- 5.0 ) than with CHOPA ( 1.0 + /- 3.0 ) . CONCLUSION No differences in time to fatigue were observed between the beverages , despite lower total carbohydrate content in the CHOPA beverage . The CHOPA beverage attenuated postexercise muscle damage , as evidence d by CK and LDH values , compared with an isocaloric CHO beverage This study examined the effects of 3 recovery drinks on endurance performance following glycogen-depleting exercise . Nine trained male cyclists performed 3 experimental trials , in a r and omized counter-balanced order , consisting of a glycogen-depleting trial , a 4-h recovery period , and a cycle to exhaustion at 70 % power at maximal oxygen uptake . At 0 and 2 h into the recovery period , participants consumed chocolate milk ( CM ) , a carbohydrate replacement drink ( CR ) , or a fluid replacement drink ( FR ) . Participants cycled 51 % and 43 % longer after ingesting CM ( 32 + /- 11 min ) than after ingesting CR ( 21 + /- 8 min ) or FR ( 23 + /- 8 min ) . CM is an effective recovery aid after prolonged endurance exercise for subsequent exercise at low-moderate intensities Coingestion of protein with carbohydrate ( CHO ) during recovery from exercise can affect muscle glycogen synthesis , particularly if CHO intake is suboptimal . Another potential benefit of protein feeding is an increased synthesis rate of muscle proteins , as is well documented after resistance exercise . In contrast , the effect of nutrient manipulation on muscle protein kinetics after aerobic exercise remains largely unexplored . We tested the hypothesis that ingesting protein with CHO after a st and ardized 2-h bout of cycle exercise would increase mixed muscle fractional synthetic rate ( FSR ) and whole body net protein balance ( WBNB ) vs. trials matched for total CHO or total energy intake . We also examined whether postexercise glycogen synthesis could be enhanced by adding protein or additional CHO to a feeding protocol that provided 1.2 g CHO x kg(-1 ) x h(-1 ) , which is the rate generally recommended to maximize this process . Six active men ingested drinks during the first 3 h of recovery that provided either 1.2 g CHO.kg(-1).h(-1 ) ( L-CHO ) , 1.2 g CHO + 0.4 g protein x kg(-1 ) x h(-1 ) ( PRO-CHO ) , or 1.6 g CHO x kg(-1 ) x h(-1 ) ( H-CHO ) in r and om order . Based on a primed constant infusion of l-[ring-(2)H(5)]phenylalanine , analysis of biopsies ( vastus lateralis ) obtained at 0 and 4 h of recovery showed that muscle FSR was higher ( P < 0.05 ) in PRO-CHO ( 0.09 + /- 0.01%/h ) vs. both L-CHO ( 0.07 + /- 0.01%/h ) and H-CHO ( 0.06 + /- 0.01%/h ) . WBNB assessed using [1-(13)C]leucine was positive only during PRO-CHO , and this was mainly attributable to a reduced rate of protein breakdown . Glycogen synthesis rate was not different between trials . We conclude that ingesting protein with CHO during recovery from aerobic exercise increased muscle FSR and improved WBNB , compared with feeding strategies that provided CHO only and were matched for total CHO or total energy intake . However , adding protein or additional CHO to a feeding strategy that provided 1.2 g CHO x kg(-1 ) x h(-1 ) did not further enhance glycogen re synthesis during recovery Nine male , endurance-trained cyclists performed an interval workout followed by 4 h of recovery , and a subsequent endurance trial to exhaustion at 70 % VO2max , on three separate days . Immediately following the first exercise bout and 2 h of recovery , subjects drank isovolumic amounts of chocolate milk , fluid replacement drink ( FR ) , or carbohydrate replacement drink ( CR ) , in a single-blind , r and omized design . Carbohydrate content was equivalent for chocolate milk and CR . Time to exhaustion ( TTE ) , average heart rate ( HR ) , rating of perceived exertion ( RPE ) , and total work ( WT ) for the endurance exercise were compared between trials . TTE and WT were significantly greater for chocolate milk and FR trials compared to CR trial . The results of this study suggest that chocolate milk is an effective recovery aid between two exhausting exercise bouts This study examined whether a carbohydrate + casein hydrolysate ( CHO+ProH ) beverage improved time-trial performance vs. a CHO beverage delivering approximately 60 g CHO/hr . Markers of muscle disruption and recovery were also assessed . Thirteen male cyclists ( VO2peak = 60.8 + /- 1.6 ml . kg-1 . min-1 ) completed 2 computer-simulated 60-km time trials consisting of 3 laps of a 20-km course concluding with a 5-km climb ( approximately 5 % grade ) . Participants consumed 200 ml of CHO ( 6 % ) or CHO+ProH beverage ( 6 % + 1.8 % protein hydrolysate ) every 5 km and 500 ml of beverage immediately postexercise . Beverage treatments were administered using a r and omly counterbalanced , double-blind design . Plasma creatine phosphokinase ( CK ) and muscle-soreness ratings were assessed immediately before and 24 hr after cycling . Mean 60-km times were 134.4 + /- 4.6 and 135.0 + /- 4.0 min for CHO+ProH and CHO beverages , respectively . All time differences between treatments occurred during the final lap , with protein hydrolysate ingestion explaining a significant ( p < .05 ) proportion of between-trials differences over the final 20 km ( 44.3 + /- 1.6 , 45.0 + /- 1.6 min ) and final 5 km ( 16.5 + /- 0.6 , 16.9 + /- 0.6 min ) . Plasma CK levels and muscle-soreness ratings increased significantly after the CHO trial ( 161 + /- 53 , 399 + /- 175 U/L ; 15.8 + /- 5.1 , 37.6 + /- 5.7 mm ) but not the CHO+ProH trial ( 115 + /- 21 , 262 + /- 88 U/L ; 20.9 + /- 5.3 , 32.2 + /- 7.1 mm ) . Late-exercise time-trial performance was enhanced with CHO+ProH beverage ingestion compared with a beverage containing CHO provided at maximal exogenous oxidation rates during exercise . CHO+ProH ingestion also prevented increases in plasma CK and muscle soreness after exercise Abstract Carbohydrate intake during endurance exercise delays the onset of fatigue and improves performance . Two recent cycling studies have reported increased time to exhaustion when protein is ingested together with carbohydrate . The purpose of the present study was to test the hypothesis that ingestion of a carbohydrate + protein beverage will lead to significant improvements in cycling time-trial performance relative to placebo and carbohydrate alone .  Thirteen cyclists completed 120 min of constant-load erg 
    Output:
    
We conclude that compared to carbohydrate alone , coingestion of protein and carbohydrate during exercise demonstrated an ergogenic effect on endurance performance when assessed by time to exhaustion and also where supplements were matched for carbohydrate ( isocarbohydrate ) .
Thus , the ergogenic effect of protein seen in isocarbohydrate studies may be because of a generic effect of adding calories ( fuel ) as opposed to a unique benefit of protein .