Long-term effects of NO3– on the relationship between oxygen uptake and power after three weeks of supplemented HIHVT

Autor: Magdalena Aleksandra Röhrich, Moritz Lützow, Dimitrios Tsikas, Norbert Maassen, Erik Hanff, Larissa Sarah Blau, Armin Finkel, Mirja Maassen
Rok vydání: 2018
Předmět:
Zdroj: Journal of Applied Physiology. 125:1997-2007
ISSN: 1522-1601
8750-7587
DOI: 10.1152/japplphysiol.00176.2018
Popis: The aim of this study was to investigate the later effects of daily [Formula: see text] supplementation over 3 wk of training on the relationship between O2 uptake and power at different intensities with an incremental test (IT), a double-wingate test (WT), and an endurance capacity test at 80% Wmax (ECT) before and after the supplementation period. Seventeen male recreational athletes participated in this double-blind placebo (PL)-controlled study. Subjects participated in a 3-wk intermittent high-intensity, high-volume training period with 45 intervals of Wmax − 10 W and an active recovery period of 10 W in between with dietary [Formula: see text] (NaNO3) or placebo supplementation (NaCl) (both 8.5 mg·kg−1·day−1) on a cycle ergometer. During a training session, plasma [[Formula: see text]] ( P < 0.001) and plasma [[Formula: see text]] ( P < 0.01) were higher in nitrate (N), whereas in pre- and posttests mean plasma [[Formula: see text]] and [[Formula: see text]] were not different between groups. In the WT [48 h after cessation of supplementation (C)], the ratio between V̇o2 and power decreased in N ( P < 0.01) with no changes in PL. Endurance capacity (4–5 days after C) similarly increased in both groups ( P < 0.01). However, the total oxygen consumption decreased by 5% ( P < 0.01) in N, with no change in PL. The slope of V̇o2·W−1 in IT (5–7 days after C) decreased in N ( P < 0.01), whereas no changes were found in PL. During low- and moderate-intensity workloads, no changes and differences in V̇o2 could be detected. We conclude that nitrate supplementation causes a sustaining reduction of the oxygen cost per watt during exercise with a large recruitment of type II muscle fibers without affecting endurance capacity. NEW & NOTEWORTHY Because most studies focused on the acute effects of [Formula: see text] supplementation on exercise performance during a supplementation period, the sustainability of the effects of the [Formula: see text] supplementation remain unknown. We followed the development of V̇o2/W at different intensities during the first week after cessation of daily [Formula: see text] supplementation over 3 wk. The results indicate that [Formula: see text] supplementation has a long-term effect for at least 7 days after cessation during heavy all-out workloads without affecting endurance capacity.
Databáze: OpenAIRE
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