title: The Effect of Dietary Nitrate Supplementation on Physiology and Performance in Trained Cyclists.
abstract: OBJECTIVE
  To determine the effect of dietary nitrate (NO3-) supplementation on physiology and performance in well-trained cyclists after 6-8 d of NO3-supplementation.
  
  
  METHODS
  Eight competitive male cyclists (mean ± SD age 26 ± 8 y, body mass 76.7 ± 6.9 kg, VO2peak63 ± 4 mL · kg-1· min-1) participated in a double-blind, placebo-controlled, crossover-design study in which participants ingested 70 mL of beetroot juice containing ~4 mmol NO3-(NIT) or a NO3--depleted placebo (PLA), each for 8 d. Replicating pretreatment measures, participants undertook an incremental ramp assessment to determine VO2peakand first (VT1) and second (VT2) ventilatory thresholds on d 6 (NIT6 and PLA6), moderate-intensity cycling economy on d 7 (NIT7 and PLA7), and a 4-km time trial (TT) on d 8 (NIT8 and PLA8).
  
  
  RESULTS
  Relative to PLA, 6 d of NIT supplementation produced unclear effects for VO2peak(mean ± 95% confidence limit: 1.8% ± 5.5%) and VT1(3.7% ± 12.3%) and trivial effects for both VT2(-1.0% ± 3.0%) and exercise economy on d 7 (-1.0% ± 1.6%). However, effects for TT performance time (-0.7% ± 0.9%) and power (2.4% ± 2.5%) on d 8 were likely beneficial.
  
  
  CONCLUSIONS
  Despite mostly unclear outcomes for standard physiological determinants of performance, 8 d of NO3-supplementation resulted in likely beneficial improvements to 4-km TT performance in well-trained male endurance cyclists.
authors.forename: Joseph A
authors.initials: JA
authors.lastname: McQuillan
authors.forename: Deborah K
authors.initials: DK
authors.lastname: Dulson
authors.forename: Paul B
authors.initials: PB
authors.lastname: Laursen
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Kilding
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000502:physiology; D000067030:Fruit and Vegetable Juices; D006801:Humans; D008297:Male; D009566:Nitrates / Q000008:administration & dosage* / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D064797:Physical Conditioning, Human
chemical_list: D009566:Nitrates
keywords: beetroot juice; cycling; economy; time trial