title: Effects of sodium phosphate and beetroot juice supplementation on repeated-sprint ability in females.
abstract: BACKGROUND
  Sodium phosphate (SP) and beetroot juice (BJ) supplementation was assessed on repeated-sprint ability (RSA).
  
  
  METHODS
  Thirteen female team-sport participants completed four trials: (1) SP and BJ (SP + BJ), (2) SP and placebo (for BJ), (3) BJ and placebo (for SP) and (4) placebo (for SP + BJ), with ~21 days separating each trial. After each trial, participants performed a simulated team-game circuit (STGC) consisting of four 15 min quarters, with a 6 × 20-m repeated-sprint set performed at the start, half-time and end.
  
  
  RESULTS
  Total sprint times were between 0.95-1.30 and 0.83-1.12 s faster for each RSA set and 3.25 and 3.12 s faster overall (~5% improvement) after SP compared with placebo and BJ, respectively (p = 0.02 for sets 1, 2 and overall; Cohen's effect size: d = -0.51 to -0.90 for all sets and overall). Additionally, total sprint times were 0.48 s faster after SP + BJ compared with placebo (set 2; p = 0.05, ~2% improvement). Furthermore, best sprints were 0.13-0.23 and 0.15-0.20 s faster (~6% improvement; p < 0.01) after SP compared with placebo and BJ, respectively, for all sets (d = -0.54 to -0.89).
  
  
  CONCLUSIONS
  SP improved RSA in team-sport, female athletes when fresh (set 1) and during the later sets of a STGC (sets 2 and 3). Specifically, total and best sprint times were faster after SP compared with placebo and BJ.
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia. buckc01@student.uwa.edu.au.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Buck
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Timothy
authors.initials: T
authors.lastname: Henry
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Kym
authors.initials: K
authors.lastname: Guelfi
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Dawson
authors.affiliation: Department of Sport and Physical Activity, Edge Hill University, St Helens Road, Ormskirk, Lancashire, L39 4QP, UK.
authors.forename: Lars R
authors.initials: LR
authors.lastname: McNaughton
authors.affiliation: School of Sport Science, Exercise and Health, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Karen
authors.initials: K
authors.lastname: Wallman
mesh_terms: D000328:Adult; D054874:Athletic Performance; D027461:Beta vulgaris / Q000737:chemistry*; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D010710:Phosphates / Q000008:administration & dosage / Q000494:pharmacology*; D010807:Physical Endurance / Q000187:drug effects*; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D010710:Phosphates; D010936:Plant Extracts; C018279:sodium phosphate
keywords: 20-m sprints; Aerobic energy; Anaerobic energy; Ergogenic aids; Team-sports