title: Dietary nitrate does not enhance running performance in elite cross-country skiers.
abstract: OBJECTIVE
  The objective of this study is to examine the effects of acute ingestion of dietary nitrate on endurance running performance in highly trained cross-country skiers. Dietary nitrate has been shown to reduce the oxygen cost of submaximal exercise and improve tolerance of high-intensity exercise, but it is not known if this holds true for highly trained endurance athletes.
  
  
  METHODS
  Ten male junior cross-country skiers (V˙O(2max)) ≈ 70 mL·kg·min) each completed two trials in a randomized, double-blind design. Participants ingested potassium nitrate (614-mg nitrate) or a nitrate-free placebo 2.5 h before two 5-min submaximal tests on a treadmill at 10 km·h (≈55% of V˙O(2max)) and 14 km·h (≈75% of V˙O(2max)), followed by a 5-km running time trial on an indoor track.
  
  
  RESULTS
  Plasma nitrite concentrations were higher after nitrate supplementation (325 ± 95 nmol·L) compared with placebo (143 ± 59 nmol·L, P < 0.001). There was no significant difference in 5-km time-trial performance between nitrate (1005 ± 53 s) and placebo treatments (996 ± 49 s, P = 0.12). The oxygen cost of submaximal running was not significantly different between placebo and nitrate trials at 10 km·h (both 2.84 ± 0.34 L·min) and 14 km·h (3.89 ± 0.39 vs. 3.77 ± 0.62 L·min).
  
  
  CONCLUSIONS
  Acute ingestion of dietary nitrate may not represent an effective strategy for reducing the oxygen cost of submaximal exercise or for enhancing endurance exercise performance in highly trained cross-country skiers.
authors.affiliation: Sport, Health and Exercise Science Research Group, Department for Health, University of Bath, Bath, United Kingdom. O.J.Peacock@bath.ac.uk
authors.forename: Oliver
authors.initials: O
authors.lastname: Peacock
authors.forename: Arnt Erik
authors.initials: AE
authors.lastname: Tjønna
authors.forename: Philip
authors.initials: P
authors.lastname: James
authors.forename: Ulrik
authors.initials: U
authors.lastname: Wisløff
authors.forename: Boye
authors.initials: B
authors.lastname: Welde
authors.forename: Nikolai
authors.initials: N
authors.lastname: Böhlke
authors.forename: Alan
authors.initials: A
authors.lastname: Smith
authors.forename: Keith
authors.initials: K
authors.lastname: Stokes
authors.forename: Christian
authors.initials: C
authors.lastname: Cook
authors.forename: Oyvind
authors.initials: O
authors.lastname: Sandbakk
mesh_terms: D000293:Adolescent; D054874:Athletic Performance; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D009566:Nitrates / Q000008:administration & dosage / Q000378:metabolism*; D009573:Nitrites / Q000097:blood; D009664:Norway; D010101:Oxygen Consumption / Q000187:drug effects; D017680:Potassium Compounds / Q000008:administration & dosage / Q000378:metabolism*; D012420:Running / Q000502:physiology*; D012865:Skiing / Q000502:physiology*
chemical_list: D009566:Nitrates; D009573:Nitrites; D017680:Potassium Compounds; C023844:potassium nitrate