***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 the study was to assess the effect of sodium bicarbonate ingestion upon repeated bouts of intensive short duration exercise . Twenty-three subjects participated in the investigation ( 8 females and 15 males , age 21.4 + /- 2.3 , mean + /- sd ) . Subjects completed six trials ; three following the ingestion of sodium bicarbonate ( 300 mg/kg body weight ) and three following the ingestion of a placebo ( 8 g sodium chloride ) . Each trial consisted of ten ten-second sprints on a cycle ergometer with 50 seconds recovery between each sprint . ' Peak power ' and ' average power output ' during each ten second sprint was measured from the flywheel of the ergometer using a light-sensitive monitor ( Cranlea ) linked to a BBC microcomputer . The power outputs recorded during each ten-second sprint of the bicarbonate trials were then compared with those recorded during the corresponding sprint of the placebo trials . The bicarbonate trials produced higher mean ' average power ' outputs in all ten of the ten-second sprints , with the difference in ' average power ' output being statistically significant in eight of these ( p less than 0.05 ) . The results also revealed that the difference in the ' average power ' outputs attained during the bicarbonate and placebo trials increased as the number of sprint repetitions increased ( p less than 0.01 ) . ' Peak power ' output was also greater in the bicarbonate trials with it being significantly higher ( p less than 0.001 ) during the final ten-second sprint . It was concluded that during exercise consisting of repeated , short- duration sprints , power output was enhanced following the ingestion of sodium bicarbonate , ( 300 mg/kg body weight ) ABSTRACT The aim of this study was to investigate the effects of sodium bicarbonate ( NaHCO3 ) on 4 km cycling time trial ( TT ) performance when individualised to a predetermined time to peak blood bicarbonate ( HCO3− ) . Eleven male trained cyclists volunteered for this study ( height 1.82 ± 0.80 m , body mass ( BM ) 86.4 ± 12.9 kg , age 32 ± 9 years , peak power output ( PPO ) 382 ± 22 W ) . Two trials were initially conducted to identify time to peak HCO3− following both 0.2 g.kg−1 BM ( SBC2 ) and 0.3 g.kg−1 BM ( SBC3 ) NaHCO3 . Thereafter , on three separate occasions using a r and omised , double-blind , crossover design , participants completed a 4 km TT following ingestion of either SBC2 , SBC3 , or a taste-matched placebo ( PLA ) containing 0.07 g.kg−1 BM sodium chloride ( NaCl ) at the predetermined individual time to peak HCO3−. Both SBC2 ( −8.3 ± 3.5 s ; p < 0.001 , d = 0.64 ) and SBC3 ( −8.6 ± 5.4 s ; p = 0.003 , d = 0.66 ) reduced the time to complete the 4 km TT , with no difference between SBC conditions ( mean difference = 0.2 ± 0.2 s ; p = 0.87 , d = 0.02 ) . These findings suggest trained cyclists may benefit from individualising NaHCO3 ingestion to time to peak HCO3− to enhance 4 km TT performance Zabala , M , Requena , B , Sánchez-Muñoz , C , González-Badillo , JJ , García , I , Ööpik , V , and Pääsuke , M. Effects of sodium bicarbonate ingestion on performance and perceptual responses in a laboratory-simulated BMX cycling qualification series . J Strength Cond Res 22(5 ) : 1645 - 1653 , 2008-The objective of this study was to examine the effect of sodium bicarbonate ( NaHCO3− ) ingestion on performance and perceptual responses in a laboratory-simulated bicycle motocross ( BMX ) qualification series . Nine elite BMX riders volunteered to participate in this study . After familiarization , subjects undertook two trials involving repeated sprints ( 3 × Wingate tests [ WTs ] separated by 30 minutes of recovery ; WT1 , WT2 , WT3 ) . Ninety minutes before each trial , subjects ingested either NaHCO3− or placebo in a counterbalanced , r and omly assigned , double-blind manner . Each trial was separated by 4 days . Performance variables of peak power , mean power , time to peak power , and fatigue index were calculated for each sprint . Ratings of perceived exertion were obtained after each sprint , and ratings of perceived readiness were obtained before each sprint . No significant differences were observed in performance variables between successive sprints or between trials . For the NaHCO3− trial , peak blood lactate during recovery was greater after WT2 ( p < 0.05 ) and tended to be greater after WT3 ( p = 0.07 ) , and ratings of perceived exertion were not influenced . However , improved ratings of perceived readiness were observed before WT2 and WT3 ( p < 0.05 ) . In conclusion , NaHCO3− ingestion had no effect on performance and RPE during a series of three WT simulating a BMX qualification series , possibly because of the short duration of each effort and the long recovery time used between the three WTs . On the contrary , NaHCO3− ingestion improved perceived readiness before each WT PURPOSE The aim of this study was to determine the effects of sodium bicarbonate ingestion on prolonged intermittent exercise and performance . METHODS Eight healthy male subjects ( mean + /- SD : age 25.4 + /- 6.4 yr , mass 70.9 + /- 5.1 kg , height 179 + /- 7 cm , VO(2max ) 4.21 + /- 0.51 L.min-1 ) volunteered for the study , which had received ethical approval . Subjects undertook two 30-min intermittent cycling trials ( repeated 3-min blocks ; 90 s at 40 % VO(2max ) , 60 s at 60 % VO(2max ) , 14-s maximal sprint , 16-s rest ) after ingestion of either sodium bicarbonate ( NaHCO(3 ) ; 0.3 g.kg-1 ) or sodium chloride ( NaCl ; 0.045 g x kg(-1 ) . Expired air , blood lactate ( BLa ) , bicarbonate ( HCO(3)- ) , and pH were measured at rest , 30 and 60 min postingestion , and during the 40 % VO(2max ) component of exercise ( 4 , 10 , 16 , and 29 min ) . RESULTS After ingestion , pH increased from rest to 7.46 + /- 0.03 and 7.40 + /- 0.01 for NaHCO(3 ) and NaCl , respectively ( main effect for time and trial ; P < 0.05 ) . Values decreased at 15 min of exercise to 7.30 + /- 0.07 and 7.21 + /- 0.06 , respectively , remaining at similar levels until the end of exercise . BLa peaked at 15 min ( 12.03 + /- 4.31 and 10.00 + /- 2.58 mmol . L-1 , for NaHCO(3 ) and NaCl , respectively ; P > 0.05 ) remaining elevated until the end of exercise ( P < 0.05 ) . Peak power expressed relative to sprint 1 demonstrated a significant main effect between trials ( P < 0.05 ) . Sprint 2 increased by 11.5 + /- 5 % and 1.8 + /- 9.5 % for NaHCO(3 ) and NaCl , respectively . During NaHCO(3 ) , sprint 8 remained similar to sprint 1 ( 0.2 + /- 17 % ) , whereas a decrease was observed during NaCl ( -10.0 + /- 16.0 % ) . CONCLUSION The results of this study suggest that ingestion of NaHCO(3 ) improves sprint performance during prolonged intermittent cycling Siegler , JC and Gleadall-Siddall , D0 . Sodium bicarbonate ingestion and repeated swim sprint performance . J Strength Cond Res 24(11 ) : 3105 - 3111 , 2010-The purpose of the present investigation was to observe the ergogenic potential of 0.3 g·kg−1 of sodium bicarbonate ( NaHCO3 ) in competitive , nonelite swimmers using a repeated swim sprint design that eliminated the technical component of turning . Six male ( 181.2 ± 7.2 cm ; 80.3 ± 11.9 kg ; 50.8 ± 5.5 ml·kg−1·min−1 & OV0312;O2max ) and 8 female ( 168.8 ± 5.6 cm ; 75.3 ± 10.1 kg ; 38.8 ± 2.6 ml·kg−1·min−1 & OV0312;O2max ) swimmers completed 2 trial conditions ( NaHCO3 [ BICARB ] and NaCl placebo [ PLAC ] ) implemented in a r and omized ( counterbalanced ) , single blind manner , each separated by 1 week . Swimmers were paired according to ability and completed 8 , 25-m front crawl maximal effort sprints each separated by 5 seconds . Blood acid-base status was assessed preingestion , pre , and postswim via capillary finger sticks , and total swim time was calculated as a performance measure . Total swim time was significantly decreased in the BICARB compared to PLAC condition ( p = 0.04 ) , with the BICARB condition result ing in a 2 % decrease in total swim time compared to the PLAC condition ( 159.4 ± 25.4 vs. 163.2 ± 25.6 seconds ; mean difference = 4.4 seconds ; 95 % confidence interval = 8.7 - 0.1 ) . Blood analysis revealed significantly elevated blood buffering potential preswim ( pH : BICARB = 7.48 ± 0.01 , PLAC = 7.41 ± 0.01 ) along with a significant decrease in extracellular K+ ( BICARB = 4.0 ± 0.1 mmol·L−1 , PLAC = 4.6 ± 0.1 mmol·L−1 ) . The findings suggest that 0.3 g·kg−1 NaHCO3 ingested 2.5 hours before exercise enhances the blood buffering potential and may positively influence swim performance Abstract We have evaluated whether sodium bicarbonate , taken chronically ( 0.5 g · kg−1 body mass ) for a period of 5 days would improve the performance of eight subjects during 60 s of high-intensity exercise on an electrically braked cycle ergometer . The first test was performed prior to chronic supplementation ( pre-ingestion ) while the post-ingestion test took place 6 days later . A control test took place approximately 1 month after the cessation of all testing . Acid-base and metabolite data ( n = 7 ) were measured from arterialised blood both pre- and post-exercise , as well as daily throughout the exercise period . The work completed by the subjects in the control and pre-ingestion test [ 21.1 ( 0.9 ) and 21.1 ( 0.9 ) MJ , respectively ] was less than ( P < 0.05 ) that completed in the post-ingestion test [ 24.1 ( 0.9 ) MJ ; F(2,21 ) = 3.4 , P < 0.05 , power = 0.57 ] . Peak power was higher after the 5-day supplementation period ( P < 0.05 ) . Ingestion of the sodium bicarbonate for a period of 5 days result ed in an increase in pH ( F(5,36 ) = 12.5 , P < 0.0001 , power = 1.0 ) over the 5-day period . The blood bicarbonate levels also rose during the trial ( P < 0.05 ) from a resting level of 22.8 ( 0.4 ) to 28.4 ( 1.1 ) mmol · l−1 after 24 h of ingestion . In conclusion , the addition of sodium bicarbonate to a normal diet proved to be of ergogenic benefit in the performance of short-term , high-intensity work PURPOSE Sodium bicarbonate ( NaHCO3 ) ingestion may prevent exercise-induced perturbations in acid-base balance , thus result ing in performance enhancement . This study aim ed to determine whether different levels of NaHCO3 intake influences acid-base balance and performance during high-intensity exercise after 5 d of supplementation . METHODS Twenty-four men ( 22 + /- 1.7 yr ) were r and omly assigned to one of three groups ( eight subjects per group ) : control ( C , placebo ) , moderate NaHCO3 intake ( MI , 0.3 g x kg(-1 ) x d(-1 ) ) , and high NaHCO3 intake ( HI , 0.5 g x kg(-1 ) x d(-1 ) ) . Arterial pH , HCO3(- ) , PO2 , PCO2 , K+ , Na , base excess ( BE ) , lactate , and mean power ( MP ) were measured before and after a Wingate test pre- and postsupplementation . RESULTS HCO3(- ) increased proportionately to the dosage level . No differences were detected 
    Output:
    
This meta- analysis provides evidence that chronic , but not acute , ingestion of NaHCO3 increases both Wingate test peak and mean power