dc.contributor.author | Vanhatalo, A | |
dc.contributor.author | Jones, AM | |
dc.contributor.author | Blackwell, JR | |
dc.contributor.author | Winyard, PG | |
dc.contributor.author | Fulford, J | |
dc.date.accessioned | 2016-06-21T13:08:37Z | |
dc.date.issued | 2014-12-15 | |
dc.description.abstract | We tested the hypothesis that the time constants (τ) of postexercise T2* MRI signal intensity (an index of O2 delivery) and muscle [PCr] (an index of metabolic perturbation, measured by (31)P-MRS) in hypoxia would be accelerated after dietary nitrate (NO3 (-)) supplementation. In a double-blind crossover design, eight moderately trained subjects underwent 5 days of NO3 (-) (beetroot juice, BR; 8.2 mmol/day NO3 (-)) and placebo (PL; 0.003 mmol/day NO3 (-)) supplementation in four conditions: normoxic PL (N-PL), hypoxic PL (H-PL; 13% O2), normoxic NO3 (-) (N-BR), and hypoxic NO3 (-) (H-BR). The single-leg knee-extension protocol consisted of 10 min of steady-state exercise and 24 s of high-intensity exercise. The [PCr] recovery τ was greater in H-PL (30 ± 4 s) than H-BR (22 ± 4 s), N-PL (24 ± 4 s) and N-BR (22 ± 4 s) (P < 0.05) and the maximal rate of mitochondrial ATP resynthesis (Qmax) was lower in the H-PL (1.12 ± 0.16 mM/s) compared with H-BR (1.35 ± 0.26 mM/s), N-PL (1.47 ± 0.28 mM/s), and N-BR (1.40 ± 0.21 mM/s) (P < 0.05). The τ of postexercise T2* signal intensity was greater in H-PL (47 ± 14 s) than H-BR (32 ± 10 s), N-PL (38 ± 9 s), and N-BR (27 ± 6 s) (P < 0.05). The postexercise [PCr] and T2* recovery τ were correlated in hypoxia (r = 0.60; P < 0.05), but not in normoxia (r = 0.28; P > 0.05). These findings suggest that the NO3 (-)-NO2 (-)-NO pathway is a significant modulator of muscle energetics and O2 delivery during hypoxic exercise and subsequent recovery. | en_GB |
dc.description.sponsorship | J. Fulford's salary was supported via National Institute of Health Research Grant 50112. | en_GB |
dc.identifier.citation | Journal of Applied Physiology, 2014, Vol. 117, no.12, pp. 1460 - 1470 | en_GB |
dc.identifier.doi | 10.1152/japplphysiol.00096.2014 | |
dc.identifier.uri | http://hdl.handle.net/10871/22199 | |
dc.language.iso | en | en_GB |
dc.publisher | American Physiological Society | en_GB |
dc.relation.url | http://www.ncbi.nlm.nih.gov/pubmed/25301896 | en_GB |
dc.rights | The final version is available from the American Physiological Society via the DOI in this record. | en_GB |
dc.subject | hypoxia | en_GB |
dc.subject | nitric oxide | en_GB |
dc.subject | nitrite | en_GB |
dc.subject | phosphocreatine | en_GB |
dc.subject | skeletal muscle | en_GB |
dc.subject | Adenosine Triphosphate | en_GB |
dc.subject | Administration, Oral | en_GB |
dc.subject | Adolescent | en_GB |
dc.subject | Adult | en_GB |
dc.subject | Anoxia | en_GB |
dc.subject | Beta vulgaris | en_GB |
dc.subject | Beverages | en_GB |
dc.subject | Biomarkers | en_GB |
dc.subject | Cross-Over Studies | en_GB |
dc.subject | Diet | en_GB |
dc.subject | Double-Blind Method | en_GB |
dc.subject | Energy Metabolism | en_GB |
dc.subject | England | en_GB |
dc.subject | Female | en_GB |
dc.subject | Humans | en_GB |
dc.subject | Kinetics | en_GB |
dc.subject | Magnetic Resonance Imaging | en_GB |
dc.subject | Magnetic Resonance Spectroscopy | en_GB |
dc.subject | Male | en_GB |
dc.subject | Mitochondria, Muscle | en_GB |
dc.subject | Muscle Contraction | en_GB |
dc.subject | Muscle, Skeletal | en_GB |
dc.subject | Nitrates | en_GB |
dc.subject | Nitric Oxide | en_GB |
dc.subject | Nitrites | en_GB |
dc.subject | Oxygen | en_GB |
dc.subject | Oxygen Consumption | en_GB |
dc.subject | Phosphocreatine | en_GB |
dc.subject | Plant Preparations | en_GB |
dc.subject | Plant Roots | en_GB |
dc.subject | Recovery of Function | en_GB |
dc.subject | Young Adult | en_GB |
dc.title | Dietary nitrate accelerates postexercise muscle metabolic recovery and O2 delivery in hypoxia. | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2016-06-21T13:08:37Z | |
dc.identifier.issn | 8750-7587 | |
exeter.place-of-publication | United States | |
dc.identifier.journal | Journal of Applied Physiology | en_GB |