Influence of dietary nitrate supplementation on physiological and muscle metabolic adaptations to sprint interval training

J Appl Physiol (1985). 2017 Mar 1;122(3):642-652. doi: 10.1152/japplphysiol.00909.2016. Epub 2016 Dec 1.


We hypothesized that 4 wk of dietary nitrate supplementation would enhance exercise performance and muscle metabolic adaptations to sprint interval training (SIT). Thirty-six recreationally active subjects, matched on key variables at baseline, completed a series of exercise tests before and following a 4-wk period in which they were allocated to one of the following groups: 1) SIT and [Formula: see text]-depleted beetroot juice as a placebo (SIT+PL); 2) SIT and [Formula: see text]-rich beetroot juice (~13 mmol [Formula: see text]/day; SIT+BR); or 3) no training and [Formula: see text]-rich beetroot juice (NT+BR). During moderate-intensity exercise, pulmonary oxygen uptake was reduced by 4% following 4 wk of SIT+BR and NT+BR (P < 0.05) but not SIT+PL. The peak work rate attained during incremental exercise increased more in SIT+BR than in SIT+PL (P < 0.05) or NT+BR (P < 0.001). The reduction in muscle and blood [lactate] and the increase in muscle pH from preintervention to postintervention were greater at 3 min of severe-intensity exercise in SIT+BR compared with SIT+PL and NT+BR (P < 0.05). However, the change in severe-intensity exercise performance was not different between SIT+BR and SIT+PL (P > 0.05). The relative proportion of type IIx muscle fibers in the vastus lateralis muscle was reduced in SIT+BR only (P < 0.05). These findings suggest that BR supplementation may enhance some aspects of the physiological adaptations to SIT.NEW & NOTEWORTHY We investigated the influence of nitrate-rich and nitrate-depleted beetroot juice on the muscle metabolic and physiological adaptations to 4 wk of sprint interval training. Compared with placebo, dietary nitrate supplementation reduced the O2 cost of submaximal exercise, resulted in greater improvement in incremental (but not severe-intensity) exercise performance, and augmented some muscle metabolic adaptations to training. Nitrate supplementation may facilitate some of the physiological responses to sprint interval training.

Keywords: beetroot juice supplementation; exercise training; muscle metabolism; training adaptation.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Adaptation, Physiological / drug effects
  • Adaptation, Physiological / physiology*
  • Administration, Oral
  • Adult
  • Athletic Performance / physiology
  • Dietary Supplements*
  • High-Intensity Interval Training / methods*
  • Humans
  • Male
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / physiology*
  • Nitrates / administration & dosage*
  • Oxygen / metabolism
  • Oxygen Consumption / drug effects
  • Oxygen Consumption / physiology*
  • Running / physiology*
  • Task Performance and Analysis


  • Nitrates
  • Oxygen