title: (In)Consistencies in Responses to Sodium Bicarbonate Supplementation: A Randomised, Repeated Measures, Counterbalanced and Double-Blind Study.
abstract: OBJECTIVE
  Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB).
  
  
  METHODS
  15 physically active males (age 25±4 y; body mass 76.0±7.3 kg; height 1.77±0.05 m) completed six cycling capacity tests at 110% of maximum power output (CCT110%) following ingestion of either 0.3 g∙kg-1BM of SB (4 trials) or placebo (PL, 2 trials). Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD) was recorded as the exercise outcome.
  
  
  RESULTS
  SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤ 0.001); absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05). Blood lactate was elevated following exercise in all trials (p ≤ 0.001), and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05), although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none.
  
  
  CONCLUSIONS
  The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT02474628.
authors.affiliation: Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of Sao Paulo, São Paulo, Brazil.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Froio de Araujo Dias
authors.affiliation: Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of Sao Paulo, São Paulo, Brazil.
authors.forename: Vinicius
authors.initials: V
authors.lastname: da Eira Silva
authors.affiliation: Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of Sao Paulo, São Paulo, Brazil.
authors.forename: Vitor
authors.initials: V
authors.lastname: de Salles Painelli
authors.affiliation: Sport, Health and Performance Enhancement (SHAPE) Research Group, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom.
authors.forename: Craig
authors.initials: C
authors.lastname: Sale
authors.affiliation: Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of Sao Paulo, São Paulo, Brazil.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Giannini Artioli
authors.affiliation: Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of Sao Paulo, São Paulo, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Gualano
authors.affiliation: Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of Sao Paulo, São Paulo, Brazil.
authors.forename: Bryan
authors.initials: B
authors.lastname: Saunders
mesh_terms: D000136:Acid-Base Equilibrium; D000328:Adult; D001642:Bicycling; D019587:Dietary Supplements; D004311:Double-Blind Method; D017079:Exercise Tolerance / Q000187:drug effects*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D017693:Sodium Bicarbonate / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D019344:Lactic Acid; D017693:Sodium Bicarbonate