title: Increase in Maximal Cycling Power With Acute Dietary Nitrate Supplementation.
abstract: Muscle-shortening velocity and hence power have been shown to increase in the presence of nitric oxide (NO). NO availability increases after consuming nitrate (NO3-). Ingestion of NO3-rich beetroot juice (BRJ) has increased muscle power in untrained adults.
  
  
  OBJECTIVE
  This study determined whether NO3-supplementation could acutely enhance maximal power in trained athletes.
  
  
  METHODS
  In this double-blind, crossover study, 13 trained athletes performed maximal inertial-load cycling trials (3-4 s) immediately before (PRE) and after (POST) consuming either NO3-rich (NO3) or NO3-depleted (PLA) BRJ to assess acute changes (ie, within the same day) in maximal power (PMAX) and optimal pedaling rate (RPMopt). Participants also performed maximal isokinetic cycling (30 s) to assess performance differences after supplementation.
  
  
  RESULTS
  2 x 2 repeated-measures ANOVA indicated a greater increase in PMAXfrom PRE to POST NO3 (PRE 1160 ± 301 W to POST 1229 ± 317 W) than with PLA (PRE 1191 ± 298 W to POST 1213 ± 300 W) (P = .009; ηp2= 0.45). A paired t-test verified a greater relative change in PMAXafter NO3 (6.0% ± 2.6%) than with PLA (2.0% ± 3.8%) (P = .014; d = 1.21). RPMoptremained unchanged from PRE (123 ± 14 rpm) to POST PLA (122 ± 14 rpm) but increased from PRE (120 ± 14 rpm) to POST NO3 (127 ± 13 rpm) (P = .043; ηp2= 0.30). There was no relative change in RPMoptafter PLA (-0.3% ± 4.1%), but there was an increase after NO3 (6.5% ± 11.4%) (P = .049; d = 0.79). No differences were observed between the 30-s isokinetic trials.
  
  
  CONCLUSIONS
  Acute NO3-supplementation can enhance maximal muscle power in trained athletes. These findings may particularly benefit power-sport athletes who perform brief explosive actions.
authors.forename: Ernest G
authors.initials: EG
authors.lastname: Rimer
authors.forename: Linda R
authors.initials: LR
authors.lastname: Peterson
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Coggan
authors.forename: James C
authors.initials: JC
authors.lastname: Martin
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000502:physiology*; D009566:Nitrates / Q000008:administration & dosage* / Q000494:pharmacology; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology; D064133:Sports Nutritional Physiological Phenomena; D055815:Young Adult
chemical_list: D009566:Nitrates; D010936:Plant Extracts
keywords: beetroot juice; ergogenic aid; inertial load; muscle power; nitric oxide