Format

Send to

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

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

Author information

1
Sport and Health Sciences, University of Exeter, Exeter, United Kingdom.
2
National Institute for Health Research Exeter Clinical Research Facility, University of Exeter, Exeter, United Kingdom; and.
3
Gatorade Sports Science Institute, PepsiCo Research & Development, Barrington, Illinois.
4
Sport and Health Sciences, University of Exeter, Exeter, United Kingdom; a.m.jones@exeter.ac.uk.

Abstract

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

PMID:
27909231
PMCID:
PMC5401949
DOI:
10.1152/japplphysiol.00909.2016
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center