***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: This study examined the effectiveness of ingesting a carbohydrate or carbohydrate + medium-chain triglycerides ( MCT ) on metabolism and cycling performance .  Eight endurance-trained men [ peak O(2 ) uptake = 4.71 + /- 0.09 ( SE ) l/min ] completed 35 kJ/kg as quickly as possible [ time trial ( TT ) ] while consuming 250 ml/15 min of either a 6 % ( wt/vol ) carbohydrate solution ( C ) , a 6 % carbohydrate + 4.2 % MCT solution ( C+M ) , or a sweet placebo ( P ) . Time to complete the set amount of work was reduced in both C and C+M compared with P by 7 and 5 % , respectively ( C : 166 + /- 7 min ; C+M : 169 + /- 7 min ; P : 178 + /- 11 min ; P < 0.01 ) . Plasma glucose concentration was maintained at or above resting values throughout both C and C+M trials but decreased ( P < 0.05 ) below resting values in P at the completion of the TT . The estimated rate of carbohydrate oxidation was not different during the first 90 min of exercise but thereafter was reduced ( P < 0.05 ) in P and was maintained in both C and C+M. These data demonstrate that carbohydrate ingestion during exercise improves 100-km TT performance compared with a sweet placebo , but the addition of MCT does not provide any further performance enhancement This study analyzed the effect of caffeine ingestion on performance during a repeated- measures , 100-km , laboratory cycling time trial that included bouts of 1- and 4-km high intensity epochs ( HIE ) . Eight highly trained cyclists participated in 3 separate trials ' placebo ingestion before exercise with a placebo carbohydrate solution and placebo tablets during exercise ( Pl ) , or placebo ingestion before exercise with a 7 % carbohydrate drink and placebo tablets during exercise ( Cho ) , or caffeine tablet ingestion before and during exercise with 7 % carbohydrate ( Caf ) . Placebo ( twice ) or 6 mg.kg(-1 ) caffeine was ingested 60 min prior to starting 1 of the 3 cycling trials , during which subjects ingested either additional placebos or a caffeine maintenance dose of 0.33 mg.kg(-1 ) every 15 min to trial completion . The 100-km time trial consisted of five 1-km HIE after 10 , 32 , 52 , 72 , and 99 km , as well as four 4-km HIE after 20 , 40 , 60 , and 80 km . Subjects were instructed to complete the time trial and all HIE as fast as possible . Plasma ( caffeine ) was significantly higher during Caf ( 0.43 + /- 0.56 and 1.11 + /- 1.78 mM pre vs. post Pl ; and 47.32 + /- 12.01 and 72.43 + /- 29.08 mM pre vs. post Caf ) . Average power , HIE time to completion , and 100-km time to completion were not different between trials . Mean heart rates during both the 1-km HIE ( 184.0 + /- 9.8 Caf ; 177.0 + /- 5.8 Pl ; 177.4 + /- 8.9 Cho ) and 4-km HIE ( 181.7 + /- 5.7 Caf ; 174.3 + /- 7.2 Pl ; 175.6 + /- 7.6 Cho ; p < .05 ) was higher in Caf than in the other groups . No significant differences were found between groups for either EMG amplitude ( IEMG ) or mean power frequency spectrum ( MPFS ) . IEMG activity and performance were not different between groups but were both higher in the 1-km HIE , indicating the absence of peripheral fatigue and the presence of a central ly-regulated pacing strategy that is not altered by caffeine ingestion . Caffeine may be without ergogenic benefit during endurance exercise in which the athlete begins exercise with a defined , predetermined goal measured as speed or distance Most studies investigating the effects of acute carbohydrate ( CHO ) ingestion on post-exercise cytokine responses have involved fasted athletes . This study characterised the effects of acute CHO beverage ingestion preceded by consumption of a CHO-containing pre-exercise meal .  Sixteen highly-trained male cyclists/triathletes ( age : 30.6 + /- 5.6 y ; V O ( 2max ) : 64.8 + /- 4.7 ml . kg . min ( -1 ) [ mean + /- SD ] ) undertook two cycle ergometry trials involving r and omised consumption of a 10 % CHO beverage ( 15 mL . kg ( -1 ) . hr ( -1 ) ) or water ( H (2)O ) . Trials were undertaken 2 h after a breakfast providing 2.1 g CHO . kg ( -1 ) body mass ( BM ) ( 48 kJ . kg ( -1 ) BM ) and consisted of 100 min steady state cycle ergometry at 70 % V O ( 2max ) followed by a time trial of approximately 30 min duration . Blood sample s were collected pre- , post- and 1 h post-exercise for measurement of Interleukin (IL)-6 , IL-8 , IL-10 and IL-1ra . Time-trial performance was not substantially different between CHO and H (2)O trials ( 4.5 % , p = 0.42 ) . Neither IL-6 nor IL-8 responses were substantially reduced in the CHO compared to the H (2)O trial . There was a substantial reduction in IL-10 ( 32 % , p = 0.05 ) and IL-1ra ( 43 % , p = 0.02 ) responses at 1 h post-exercise with CHO compared to H (2)O ingestion . In conclusion , the previously shown attenuating effects of CHO ingestion during exercise on cytokine responses appear reduced when athletes consume a CHO-containing pre-exercise meal The study examined the effect of carbohydrate ingestion on exercise performance capacity .  Nine male cyclists performed two separate trials at 70 % VO2max for 60 min followed by a maximal ride for 10 min . During trials subjects were fed either an 8 % glucose solution ( CHO ) or a placebo solution ( PL ) , which were administered at rest and during and immediately after submaximal exercise . Statistical analyses indicated that glucose levels at rest increased significantly 15 min after the ingestion of CHO compared to PL . At 30 and 60 min during submaximal exercise , plasma glucose levels decreased significantly in the CHO but not in the PL trial . Following the performance ride , glucose levels increased significantly only during the CHO test trial . Free fatty acids did not change significantly during testing trials . The maximal performance ride results showed that in the CHO trial , a significantly greater external work load was accomplished compared to the PL trial . It is concluded that CHO ingestion improves maximal exercise performance after prolonged exercise PURPOSE Five days of a high-fat diet produce metabolic adaptations that increase the rate of fat oxidation during prolonged exercise . We investigated whether enhanced rates of fat oxidation during submaximal exercise after 5 d of a high-fat diet would persist in the face of increased carbohydrate ( CHO ) availability before and during exercise . METHODS Eight well-trained subjects consumed either a high-CHO ( 9.3 g x kg(-1 ) x d(-1 ) CHO , 1.1 g x kg(-1 ) x d(-1 ) fat ; HCHO ) or an isoenergetic high-fat diet ( 2.5 g x kg(-1 ) x d(-1 ) CHO , 4.3 g x kg(-1 ) x d(-1 ) fat ; FAT-adapt ) for 5 d followed by a high-CHO diet and rest on day 6 . On day 7 , performance testing ( 2 h steady-state ( SS ) cycling at 70 % peak O(2 ) uptake [ VO(2peak ) ] + time trial [ TT ] ) of 7 kJ x kg(-1 ) ) was undertaken after a CHO breakfast ( CHO 2 g x kg(-1 ) ) and intake of CHO during cycling ( 0.8 g x kg(-1 ) x h(-1 ) ) . RESULTS FAT-adapt reduced respiratory exchange ratio ( RER ) values before and during cycling at 70 % VO(2peak ) ; RER was restored by 1 d  CHO  and  CHO  intake during cycling ( 0.90 + /- 0.01 , 0.80 + /- 0.01 , 0.91 + /- 0.01 , for days 1 , 6 , and 7 , respectively ) . RER values were higher with HCHO ( 0.90 + /- 0.01 , 0.88 + /- 0.01 ( HCHO > FAT-adapt , P < 0.05 ) , 0.95 + /- 0.01 ( HCHO > FAT-adapt , P < 0.05 ) ) . On day 7 , fat oxidation remained elevated ( 73 + /- 4 g vs 45 + /- 3 g , P < 0.05 ) , whereas CHO oxidation was reduced ( 354 + /- 11 g vs 419 + /- 13 g , P < 0.05 ) throughout SS in FAT-adapt versus HCHO . TT performance was similar for both trials ( 25.53 + /- 0.67 min vs 25.45 + /- 0.96 min , NS ) . CONCLUSION Adaptations to a short-term high-fat diet persisted in the face of high CHO availability before and during exercise , but failed to confer a performance advantage during a TT lasting approximately 25 min undertaken after 2 h of submaximal cycling We evaluated the effect of carbohydrate ( CHO ) loading on cycling performance that was design ed to be similar to the dem and s of competitive road racing . Seven well-trained cyclists performed two 100-km time trials ( TTs ) on separate occasions , 3 days after either a CHO-loading ( 9 g CHO . kg body mass(-1 ) . day(-1 ) ) or placebo-controlled moderate-CHO diet ( 6 g CHO . kg body mass(-1 ) . day(-1 ) ) . A CHO breakfast ( 2 g CHO/kg body mass ) was consumed 2 h before each TT , and a CHO drink ( 1 g CHO . kg(.)body mass(-1 ) . h(-1 ) ) was consumed during the TTs to optimize CHO availability . The 100-km TT was interspersed with four 4-km and five 1-km sprints . CHO loading significantly increased muscle glycogen concentrations ( 572 + /- 107 vs. 485 + /- 128 mmol/kg dry wt for CHO loading and placebo , respectively ; P < 0.05 ) . Total muscle glycogen utilization did not differ between trials , nor did time to complete the TTs ( 147.5 + /- 10.0 and 149.1 + /- 11.0 min ; P = 0.4 ) or the mean power output during the TTs ( 259 + /- 40 and 253 + /- 40 W , P = 0.4 ) . This placebo-controlled study shows that CHO loading did not improve performance of a 100-km cycling TT during which CHO was consumed . By preventing any fall in blood glucose concentration , CHO ingestion during exercise may offset any detrimental effects on performance of lower preexercise muscle and liver glycogen concentrations . Alternatively , part of the reported benefit of CHO loading on subsequent athletic performance could have result ed from a placebo effect It is presently unclear whether the reported ergogenic effect of a carbohydrate ( CHO ) mouth rinse on cycling time-trial performance is affected by the acute nutritional status of an individual . Hence , the aim of this study was to investigate the effect of a CHO mouth rinse on a 60-min simulated cycling time-trial performance commenced in a fed or fasted state . Twelve competitive male cyclists each completed 4 experimental trials using a double-blinded Latin square design . Two trials were commenced 2 h after a meal that contained 2.5 g·kg(-1 ) body mass of CHO ( FED ) and 2 after an overnight fast ( FST ) . Prior to and after every 12.5 % of total time during a performance ride , either a 10 % maltodextrin ( CHO ) or a taste-matched placebo ( PLB ) solution was mouth rinsed for 10 s then immediately expectorated . There were significant main effects for both pre-ride nutritional status ( FED vs. FST ; p < 0.01 ) and CHO mouth rinse ( CHO vs. PLB ; p < 0.01 ) on power output with an interaction evident between the interventions ( p < 0.05 ) . The CHO mouth rinse improved mean power to a greater extent after an overnight fast ( 282 vs. 273 W , 3.4 % ; p < 0.01 ) compared with a fed state ( 286 vs. 281 W , 1.8 % ; p < 0.05 ) . We concluded that a CHO mouth rinse  improved performance to a greater extent in a fasted compared with a fed state ; however , optimal performance was achieved in a fed state with the addition of a CHO mouth rinse The effects of 
    Output:
    
Conclusion Due to the limitations of this systematic review , results can only be applied to a subset of athletes ( trained male cyclists ) .
For those , we could observe a potential ergogenic benefit of carbohydrate supplementation especially in a concentration range between 6 and 8 % when exercising longer than 90 min