Dietary Nitrate Supplementation Is Not Helpful for Endurance Performance at Simulated Altitude Even When Combined With Intermittent Normobaric Hypoxic Training.

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Version: Final published version
License: CC BY 4.0
Serval ID
serval:BIB_14FB5B980F6C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Dietary Nitrate Supplementation Is Not Helpful for Endurance Performance at Simulated Altitude Even When Combined With Intermittent Normobaric Hypoxic Training.
Journal
Frontiers in physiology
Author(s)
Sousa A., Viana J.L., Milheiro J., Reis V.M., Millet G.P.
ISSN
1664-042X (Print)
ISSN-L
1664-042X
Publication state
Published
Issued date
2022
Peer-reviewed
Oui
Volume
13
Pages
839996
Language
english
Notes
Publication types: Journal Article
Publication Status: epublish
Abstract
Training intensity and nutrition may influence adaptations to training performed in hypoxia and consequently performance outcomes at altitude. This study investigates if performance at simulated altitude is improved to a larger extent when high-intensity interval training is performed in normobaric hypoxia and if this is potentiated when combined with chronic dietary nitrate (NO <sub>3</sub> <sup>-</sup> ) supplementation.
Thirty endurance-trained male participants were allocated to one of three groups: hypoxia (13% F <sub>i</sub> O <sub>2</sub> ) + NO <sub>3</sub> <sup>-</sup> ; hypoxia + placebo; and normoxia (20.9% F <sub>i</sub> O <sub>2</sub> ) + placebo. All performed 12 cycling sessions (eight sessions of 2*6 × 1 min at severe intensity with 1 min recovery and four sessions of 4*6*10 s all-out with 20 s recovery) during a 4-week period (three sessions/week) with supplementation administered 3-2.5 h before each session. An incremental exhaustion test, a severe intensity exercise bout to exhaustion (T <sub>lim</sub> ) and a 3 min all-out test (3AOT) in hypoxia (F <sub>i</sub> O <sub>2</sub> = 13%) with pulmonary oxygen uptake ( O <sub>2</sub> ), O <sub>2</sub> kinetics, and changes in vastus lateralis local O <sub>2</sub> saturation (SmO <sub>2</sub> ) measured were completed by each participant before and after training.
In all tests, performance improved to the same extent in hypoxia and normoxia, except for SmO <sub>2</sub> after T <sub>lim</sub> (p = 0.04, d = 0.82) and 3AOT (p = 0.03, d = 1.43) which were lower in the two hypoxic groups compared with the normoxic one. Dietary NO <sub>3</sub> <sup>-</sup> supplementation did not bring any additional benefits.
Performance at simulated altitude was not improved to a larger extent when high-intensity interval training was undertaken in normobaric hypoxic conditions, when compared with normoxic training. Additionally, dietary NO <sub>3</sub> <sup>-</sup> supplementation was ineffective in further enhancing endurance performance at simulated altitude.
Keywords
endurance, hypoxia, intermittent training, nitrate, performance
Pubmed
Open Access
Yes
Create date
11/04/2022 9:14
Last modification date
27/09/2022 6:39
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