title: Acute versus chronic supplementation of sodium citrate on 200 m performance in adolescent swimmers.
abstract: 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∙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.
  
  
  BACKGROUND
  Clinicaltrials.gov NCT01835912.
authors.affiliation: Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Av., St. Catharines, Ontario L2S 3A1, Canada.
authors.forename: Colin
authors.initials: C
authors.lastname: Russell
authors.affiliation: Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Av., St. Catharines, Ontario L2S 3A1, Canada.
authors.forename: Efthymios
authors.initials: E
authors.lastname: Papadopoulos
authors.affiliation: Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Av., St. Catharines, Ontario L2S 3A1, Canada.
authors.forename: Yasmeen
authors.initials: Y
authors.lastname: Mezil
authors.affiliation: Faculty of Kinesiology and Physical Education, University of Toronto, 55 Harbord St., Toronto, Ontario M5S 2W6, Canada.
authors.forename: Greg D
authors.initials: GD
authors.lastname: Wells
authors.affiliation: Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Av., St. Catharines, Ontario L2S 3A1, Canada.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Plyley
authors.affiliation: Michael G. DeGroote School of Medicine, McMaster University, 500 Glenridge Av., St. Catharines, Ontario L2S 3A1, Canada.
authors.forename: Mathew
authors.initials: M
authors.lastname: Greenway
authors.affiliation: Department of Kinesiology, Faculty of Applied Health Sciences, Brock University, 500 Glenridge Av., St. Catharines, Ontario L2S 3A1, Canada.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Klentrou
keywords: Alkalization; Bicarbonate; Blood lactate; Buffer; Ergogenic aid; Responders