title: No improvement of repeated-sprint performance with dietary nitrate.
abstract: OBJECTIVE
  Nitrate supplementation improves endurance exercise and single bouts of high-intensity activity, but its effect on repeated sprints is unclear. This study is the first to investigate the effects of acute dietary nitrate supplementation during a high-intensity intermittent-sprint test to exhaustion.
  
  
  METHODS
  Team-sport athletes (9 male, age 22.3 ± 2.1 y, VO2max 57.4 ± 8.5 mL · kg-1 · min-1; 7 female, age 20.7 ± 1.3 y, VO2max 47.2 ± 8.5 mL · kg-1 · min-1) were assigned to a double-blind, randomized, crossover design. Participants consumed 70 mL of concentrated beetroot juice containing a minimum of 0.3 g of nitrate (NT) or 70 mL of placebo (PL) 2 h before a repeated-sprint protocol involving repeated 8-s sprints with 30-s recovery on a cycle ergometer to exhaustion.
  
  
  RESULTS
  Fewer sprints (NT = 13 ± 5 vs PL = 15 ± 6, P = .005, d = 0.41) and less total work (NT = 49.2 ± 24.2 kJ vs PL = 57.8 ± 34.0 kJ, P = .027, d = 0.3) were completed in NT relative to PL. However there was no difference in overall mean power output or the mean power output for each individual 8-s sprint.
  
  
  CONCLUSIONS
  These findings suggest that dietary nitrate is not beneficial for improving repeated-sprint performance, at least when such sprints are near-maximal and frequent in nature. The lack of an effect of nitrate at near-maximal oxygen uptake supports the suggestion that at greater exercise intensities nitrate does not have an ergogenic effect.
authors.affiliation: University of Canberra National Inst of Sport Studies (UCNISS), Canberra, ACT, Australia.
authors.forename: Kristy
authors.initials: K
authors.lastname: Martin
authors.forename: Disa
authors.initials: D
authors.lastname: Smee
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Thompson
authors.forename: Ben
authors.initials: B
authors.lastname: Rattray
mesh_terms: D000328:Adult; D054874:Athletic Performance; D020958:Australian Capital Territory; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018763:Muscle Fatigue / Q000187:drug effects; D053580:Muscle Strength / Q000187:drug effects; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D009566:Nitrates / Q000008:administration & dosage*; D010101:Oxygen Consumption / Q000187:drug effects; D010465:Perception; D058573:Performance-Enhancing Substances / Q000008:administration & dosage*; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D009566:Nitrates; D058573:Performance-Enhancing Substances; D019344:Lactic Acid