title: The Reproducibility of Blood Acid Base Responses in Male Collegiate Athletes Following Individualised Doses of Sodium Bicarbonate: A Randomised Controlled Crossover Study.
abstract: BACKGROUND
  Current evidence suggests sodium bicarbonate (NaHCO3) should be ingested based upon the individualised alkalotic peak of either blood pH or bicarbonate (HCO3-) because of large inter-individual variations (10-180 min). If such a strategy is to be practical, the blood analyte response needs to be reproducible.
  
  
  OBJECTIVE
  This study aimed to evaluate the degree of reproducibility of both time to peak (TTP) and absolute change in blood pH, HCO3-and sodium (Na+) following acute NaHCO3ingestion.
  
  
  METHODS
  Male participants (n = 15) with backgrounds in rugby, football or sprinting completed six randomised treatments entailing ingestion of two doses of 0.2 g·kg-1body mass (BM) NaHCO3(SBC2a and b), two doses of 0.3 g·kg-1BM NaHCO3(SBC3a and b) or two control treatments (CON1a and b) on separate days. Blood analysis included pH, HCO3-and Na+prior to and at regular time points following NaHCO3ingestion over a 3-h period.
  
  
  RESULTS
  HCO3-displayed greater reproducibility than pH in intraclass correlation coefficient (ICC) analysis for both TTP (HCO3-SBC2 r = 0.77, P = 0.003; SBC3 r = 0.94, P < 0.001; pH SBC2 r = 0.62, P = 0.044; SBC3 r = 0.71, P = 0.016) and absolute change (HCO3-SBC2 r = 0.89, P < 0.001; SBC3 r = 0.76, P = 0.008; pH SBC2 r = 0.84, P = 0.001; SBC3 r = 0.62, P = 0.041).
  
  
  CONCLUSIONS
  Our results indicate that both TTP and absolute change in HCO3-is more reliable than pH. As such, these data provide support for an individualised NaHCO3ingestion strategy to consistently elicit peak alkalosis before exercise. Future work should utilise an individualised NaHCO3ingestion strategy based on HCO3-responses and evaluate effects on exercise performance.
authors.affiliation: Department of Sport and Physical Activity, Edge Hill University, Ormskirk, Lancashire, L39 4QP, UK. goughl@edgehill.ac.uk.
authors.forename: Lewis A
authors.initials: LA
authors.lastname: Gough
authors.affiliation: Department of Sport and Physical Activity, Edge Hill University, Ormskirk, Lancashire, L39 4QP, UK.
authors.forename: Sanjoy K
authors.initials: SK
authors.lastname: Deb
authors.affiliation: Department of Sport and Physical Activity, Edge Hill University, Ormskirk, Lancashire, L39 4QP, UK.
authors.forename: Andy S
authors.initials: AS
authors.lastname: Sparks
authors.affiliation: Department of Sport and Physical Activity, Edge Hill University, Ormskirk, Lancashire, L39 4QP, UK.
authors.forename: Lars R
authors.initials: LR
authors.lastname: McNaughton
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D015444:Exercise; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007206:Individuality; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D015203:Reproducibility of Results; D012964:Sodium; D017693:Sodium Bicarbonate / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D019344:Lactic Acid; D017693:Sodium Bicarbonate; D012964:Sodium
keywords: Absolute Change; Carnosine; HCO3; Intraclass Correlation Coefficient; NaHCO3