title: Impact of acute sodium citrate ingestion on endurance running performance in a warm environment.
abstract: OBJECTIVE
  Dietary supplements inducing alkalosis have been shown to be ergogenic during intense endurance exercise in temperate environments, but there is lack of data regarding the efficacy of these substances in the heat. This study aimed to investigate the effect of sodium citrate (CIT) ingestion on 5,000-m running performance in a warm environment.
  
  
  METHODS
  Sixteen non-heat-acclimated endurance-trained males (age 25.8 ± 4.4 years, VO2peak 56.9 ± 4.7 mL kg min) completed two 5,000-m self-paced treadmill runs with preceding CIT or placebo (wheat flour; PLC) ingestion in a double-blind, randomized, crossover manner in a climatic chamber (air temperature 32 °C, relative humidity 50 %).
  
  
  RESULTS
  CIT ingestion (500 mg kg(-1) body mass) compared to PLC induced increases in water retention, body mass and plasma volume (P < 0.05). Pre- and post-exercise blood HCO3 (-) concentration, base excess and pH were higher (P < 0.001) in CIT compared to PLC trial. Rectal temperature, body heat storage, heat storage rate, heart rate and 5,000-m running time (18.92 ± 2.05 min in CIT, 19.11 ± 2.38 min in PLC; 66 % likelihood of benefit, d = -0.09) were similar (P > 0.05) in the two trials. Post-exercise blood lactate concentration was higher (P < 0.001) in CIT (11.05 ± 3.22 mmol L(-1)) compared to PLC trial (8.22 ± 2.64 mmol L(-1)). Ratings of perceived exertion, fatigue and thermal sensation did not differ in the two trials (P > 0.05).
  
  
  CONCLUSIONS
  Acute CIT ingestion induces alkalosis, water retention, plasma volume expansion and an increase in post-exercise blood lactate concentration, but does not improve 5,000-m running performance in a warm environment in non-heat-acclimated endurance-trained males.
authors.affiliation: Tartu Health Care College, Tartu, Estonia.
authors.forename: Ivi
authors.initials: I
authors.lastname: Vaher
authors.forename: Saima
authors.initials: S
authors.lastname: Timpmann
authors.forename: Martin
authors.initials: M
authors.lastname: Aedma
authors.forename: Vahur
authors.initials: V
authors.lastname: Ööpik
mesh_terms: D000284:Administration, Oral; D000328:Adult; D054874:Athletic Performance; D002951:Citrates / Q000008:administration & dosage / Q000494:pharmacology*; D006358:Hot Temperature; D006801:Humans; D008297:Male; D010807:Physical Endurance / Q000187:drug effects*; D012420:Running; D000077559:Sodium Citrate
chemical_list: D002951:Citrates; D000077559:Sodium Citrate