Acute versus chronic supplementation of sodium citrate on 200 m performance in adolescent swimmers

Background: a double-blinded,placebo-controlled,cross-over design was used to investigate whether two different sodium citrate dihydrate (na-cit) supplementation protocols improve 200 m swimming performance in adolescent swimmers.methods: ten,male swimmers (14.9 ± 0.4 years of age; 63.5 ± 4 kg) performed four 200 m time trials with the following treatments: acute (acu) supplementation (0.5 g kg-1 administered 120 min pre-trial),acute placebo (plc-a),chronic (chr) supplementation (0.1 g{bullet operator}kg-1 for three days and 0.3 g kg-1 on the forth day 120 min pre-trial),and chronic placebo (plc-c). the order of the trials was randomized,with at least a six-day wash-out period between trials. blood samples were collected by finger prick pre-ingestion,100 min post-ingestion,and 3 min post-trial. performance time,rate of perceived exertion,ph,base excess,bicarbonate and lactate concentration were measured.results: post-ingestion bicarbonate and base excess were higher (p < 0.05) in both the acu and chr trials compared to placebo showing adequate pre-exercise alkalosis. however,performance time,rate of perceived exertion as well as post-trial ph and lactate concentration were not significantly different between trials. further analysis revealed that five swimmers,identified as responders,improved their performance time by 1.03% (p < 0.05) and attained higher post-trial lactate concentrations in the acu versus plc-a trial (p < 0.05). they also had significantly higher post-trial lactate concentrations compared to the non-responders in the acu and chr trials.conclusions: acute supplementation of na-cit prior to 200 m swimming performance led to a modest time improvement and higher blood lactate concentrations in only half of the swimmers while the chronic na-cit supplementation did not provide any ergogenic effect in this group of adolescent swimmers.trial registration: clinicaltrials.gov nct01835912. © 2014 russell et al.; licensee biomed central ltd.