title: Effects of sodium phosphate and caffeine loading on repeated-sprint ability.
abstract: The effects of sodium phosphate and caffeine supplementation were assessed on repeated-sprint ability. Using a randomised, double-blind, Latin-square design, 12 female, team-sport players participated in four trials: (1) sodium phosphate and caffeine, (2) sodium phosphate and placebo (for caffeine), (3) caffeine and placebo (for sodium phosphate) and (4) placebo (for sodium phosphate and caffeine), with ~21 days separating each trial. After each trial, participants performed a simulated team-game circuit (4 × 15 min quarters) with 6 × 20-m repeated-sprints performed once before (Set 1), at half-time (Set 2), and after end (Set 3). Total sprint times were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 1: P = 0.003; Set 2: d = -0.51; Set 3: P < 0.001; overall: P = 0.020), caffeine (Set 3: P = 0.004; overall: P = 0.033) and sodium phosphate (Set 3: d = -0.67). Furthermore, total sprint times were faster after sodium phosphate supplementation compared with placebo (Set 1: d = -0.52; Set 3: d = -0.58). Best sprint results were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 3: P = 0.007, d = -0.90) and caffeine (Set 3: P = 0.024, d = -0.73). Best sprint times were also faster after sodium phosphate supplementation compared with placebo (d = -0.54 to -0.61 for all sets). Sodium phosphate and combined sodium phosphate and caffeine loading improved repeated-sprint ability.
authors.affiliation: a The University of Western Australia , School of Sport Science, Exercise and Health , Perth , Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Buck
authors.affiliation: a The University of Western Australia , School of Sport Science, Exercise and Health , Perth , Australia.
authors.forename: Kym
authors.initials: K
authors.lastname: Guelfi
authors.affiliation: a The University of Western Australia , School of Sport Science, Exercise and Health , Perth , Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Dawson
authors.affiliation: b Edge Hill University , Sport and Physical activity , Lancashire , UK.
authors.forename: Lars
authors.initials: L
authors.lastname: McNaughton
authors.affiliation: a The University of Western Australia , School of Sport Science, Exercise and Health , Perth , Australia.
authors.forename: Karen
authors.initials: K
authors.lastname: Wallman
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D002110:Caffeine / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D002149:Energy Intake; D005260:Female; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D010465:Perception; D010710:Phosphates / Q000008:administration & dosage*; D005082:Physical Exertion / Q000502:physiology; D012420:Running / Q000502:physiology*; D055815:Young Adult
chemical_list: D010710:Phosphates; D019344:Lactic Acid; D002110:Caffeine; C018279:sodium phosphate
keywords: 20-metre sprints; aerobic exercise; anaerobic exercise; ergogenic aids