***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: PURPOSE This study aim ed to investigate carbohydrate ( CHO ) mouth rinse response on neuromuscular activity , fuel oxidation rates , and cycling performance with different initial levels of endogenous CHO availability . METHODS In a double-blind , r and omized placebo-controlled design , eight males completed six experimental mouth rinse trials : CHO ( 6.4 % maltodextrin ) or placebo solution in a fed state ( FED ) , 12-h fasted state ( FAST ) , or a combined exercise-depleted muscle glycogen and 12-h fasted state ( DEP ) . Trials consisted of 30-min cycling at 90 % of gas exchange threshold , followed by a 20-km cycling time trial . Plasma lactate , plasma glucose , oxygen uptake , and EMG activity were measured , and CHO and fat oxidation rates were calculated . RESULTS CHO mouth rinse maintained higher plasma glucose levels as the constant load exercise progressed ( P = 0.023 ) . The reduced EMG activity in the DEP condition with the placebo during constant load exercise was ameliorated with CHO mouth rinse ( P < 0.01 ) . Furthermore , the power output and the EMG activity throughout the 20-km time trial were reduced in the DEP condition with placebo but were both restored with CHO mouth rinse ( P < 0.05 ) . Time trial performance was only improved with CHO in the DEP compared with the corresponding placebo ( P < 0.05 ) , and no differences between supplements were observed in the FED or FAST states . Analyses of the qualitative inference showed " benefit very likely " of CHO mouth rinse on exercise performance in DEP , " possibly benefit " in FAST , and " negligible or trivial " in FED . CHO mouth rinse had no effect on CHO and fat oxidation rates in either exercise mode . CONCLUSION The CHO mouth rinse influences exercise performance when endogenous CHO availability is low , and an enhanced central motor drive is potentially the main influencing mechanism The carbohydrate ( CHO ) concentration of a mouth rinsing solution might influence the CHO sensing receptors in the mouth , with consequent activation of brain regions involved in reward , motivation and regulation of motor activity . The purpose of the present study was to examine the effects of maltodextrin mouth rinsing with different concentrations ( 3 % , 6 % and 12 % ) after an overnight fast on a 20 km cycling time trial performance . Nine recreationally active , healthy males ( age : 24 ± 2 years ; V˙O2max : 47 ± 5 mL·kg−1·min−1 ) participated in this study . A double-blind , placebo-controlled r and omized study was conducted . Participants mouth-rinsed every 2.5 km for 5 s. Maltodextrin mouth rinse with concentrations of 3 % , 6 % or 12 % did not change time to complete the time trial and power output  compared to placebo (  p > 0.05 ) . Time trial completion times were 40.2 ± 4.0 , 40.1 ± 3.9 , 40.1 ± 4.4 , and 39.3 ± 4.2 min and power output 205 ± 22 , 206 ± 25 , 210 ± 24 , and 205 ± 23 W for placebo , 3 % , 6 % , and 12 % maltodextrin conditions , respectively . Heart rate , lactate , glucose , and rating of perceived exertion did not differ between trials ( p > 0.05 ) . In conclusion , mouth rinsing with different maltodextrin concentrations after an overnight fast did not affect the physiological responses and performance during a 20 km cycling time trial in recreationally active males 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 Abstract Ispoglou , T , O'Kelly , D , Angelopoulou , A , Bargh , M , O'Hara , JP , and Duckworth , LC . Mouth rinsing with carbohydrate solutions at the postpr and ial state fail to improve performance during simulated cycling time trials . J Strength Cond Res 29(8 ) : 2316–2325 , 2015—Mouth rinsing with carbohydrate ( CHO ) solutions during cycling time trials results in performance enhancements ; however , most studies have used approximately 6 % CHO solutions . Therefore , the purpose of this study was to compare the effectiveness of mouth rinsing with 4 , 6 , and 8 % CHO solutions on 1-hour simulated cycling time trial performance . On 4 occasions , 7 trained male cyclists completed at the postpr and ial period , a set amount of work as fast as possible in a r and omized counterbalanced order . The subjects rinsed their mouth for 5 seconds , on completion of each 12.5 % of the trial , with 25 ml of a non-CHO placebo and 4 , 6 , and 8 % CHO solutions . No additional fluids were consumed during the time trial . Heart rate ( HR ) , ratings of perceived exertion ( RPE ) , thirst ( TH ) , and subjective feelings ( SF ) were recorded after each rinse . Furthermore , blood sample s were drawn every 25 % of the trial to measure blood glucose and blood lactate concentrations , whereas whole-body CHO oxidation was monitored continuously . Time to completion was not significant between conditions with the placebo , 4 , 6 , and 8 % conditions completing the trials in 62.0 ± 3.0 , 62.8 ± 4.0 , 63.4 ± 3.4 , and 63 ± 4.0 minutes , respectively . There were no significant differences between conditions in any of the variables mentioned above ; however , significant time effects were observed for HR , RPE , TH , and SF . Post hoc analysis showed that TH and SF of subjects in the CHO conditions but not in the placebo were significantly increased by completion of the time trial . In conclusion , mouth rinsing with CHO solutions did not impact 1-hour cycling performance in the postpr and ial period and in the absence of fluid intake . Our findings suggest that there is scope for further research to explore the activation regions of the brain and whether they are receptive to CHO dose , before specific recommendations for athletic population s are established . Consequently , mouth rinsing as a practical strategy for coaches and athletes is question able under specific conditions and should be carefully considered before its inclusion . Emphasis should be focused on appropriate dietary and fluid strategies during training and competition PURPOSE AND METHOD To investigate the possible role of carbohydrate ( CHO ) receptors in the mouth in influencing exercise performance , seven male and two female endurance cyclists ( VO(2max ) 63.2 + /- 2.7 ( mean + /- SE ) mL.kg*(-1).min(-1 ) ) completed two performance trials in which they had to accomplish a set amount of work as quickly as possible ( 914 + /- 40 kJ ) . On one occasion a 6.4 % maltodextrin solution ( CHO ) was rinsed around the mouth for every 12.5 % of the trial completed . On the other occasion , water ( PLA ) was rinsed . Subjects were not allowed to swallow either the CHO solution or water , and each mouthful was spat out after a 5-s rinse . RESULTS Performance time was significantly improved with CHO compared with PLA ( 59.57 + /- 1.50 min vs 61.37 + /- 1.56 min , respectively , P = 0.011 ) . This improvement result ed in a significantly higher average power output during the CHO compared with the PLA trial ( 259 + /- 16 W and 252 + /- 16 W , respectively , P = 0.003 ) . There were no differences in heart rate or rating of perceived exertion ( RPE ) between the two trials ( P > 0.05 ) . CONCLUSION The results demonstrate that carbohydrate mouth rinse has a positive effect on 1-h time trial performance . The mechanism responsible for the improvement in high-intensity exercise performance with exogenous carbohydrate appears to involve an increase in central drive or motivation rather than having any metabolic cause . The nature and role of putative CHO receptors in the mouth warrants further investigation 
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Interestingly , careful analysis of the plots by Li et al. [ 1 ] revealed that the study by Pottier et al. [ 4 ] ( using an approximately 3 h restricted alimentary state ) impacted the results as much as some overnight fasting studies [ 5 , 6 ] , thus suggesting that different pr and ial states may have only negligible influence on the ergogenic benefit of CHO mouth rinse .
For example , a recent study [ 17 ] showed that CHO mouth rinse had negligible effect on 20 km cycling time trial performance when the pre-exercise endogenous glycogen levels ( muscle and probably liver ) were adequate in the fed or fasted state condition .