***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 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 Background The hypothesis of the central effect of carbohydrate mouth rinse ( CMR ) on performance improvement in a fed state has not been established , and its psychophysiological responses have not yet been described . The aim of this study was to evaluate the effect of CMR in athletes fed state on performance , biochemical and psychophysiological responses compared to ad libitum water intake . Methods Eleven trained male cyclists completed a r and omized , crossover trial , which consisted of a 30 km cycle ergometer at self-selected intensity and in a fed state . Subjects were under r and om influence of the following interventions : CMR with a 6 % unflavored maltodextrin solution ; mouth rinsing with a placebo solution ( PMR ) ; drinking “ ad libitum ” ( DAL ) . The time for completion of the test ( min ) , heart rate ( bpm ) and power ( watts ) , rating of perceived exertion ( RPE ) , affective response , blood glucose ( mg/dL ) and lactate ( mmol/DL ) , were evaluated before , during and immediately after the test , while insulin ( uIL/mL ) , cortisol ( μg/dL ) and creatine kinase ( U/L ) levels were measured before , immediately after the test and 30 min after the test . Results Time for completion of the 30 km trial did not differ significantly among CMR , PMR and DAL interventions ( means = 54.5 ± 2.9 , 54.7 ± 2.9 and 54.5 ± 2.5 min , respectively ; p = 0.82 ) . RPE and affective response were higher in DAL intervention ( p < 0.01 ) . Glucose , insulin , cortisol and creatine kinase responses showed no significant difference among interventions . Conclusions In a fed state , CMR has not caused metabolic changes , and it has not improved physical performance compared to ad libitum water intake , but demonstrated a possible central effect . ReBec registration number : RBR-4vpwkg . Available in http://www.ensaiosclinicos.gov.br/rg/?q=RBR-4vpwkg 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 
    Output:
    
Even when using calculations recommended for crossover design s we observed that CHO mouth rinse has the potential to improve cycling mean power output , but time does not .