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Influence of dietary nitrate supplementation on local sweating and cutaneous vascular responses during exercise in a hot environment

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journal contribution
posted on 30.05.2018, 15:48 authored by Tatsuro Amano, Dai Okushima, Brynmor C. Breese, Stephen BaileyStephen Bailey, Shunsaku Koga, N. Kondo
Purpose We investigated the influence of inorganic nitrate (NO−3) supplementation on local sweating and cutaneous vascular responses during exercise in hot conditions. Method Eight healthy, young subjects were assigned in a randomized, double-blind, crossover design to receive NO−3 -rich beetroot (BR) juice (140 mL/day, containing ~8 mmol of NO−3) and NO−3-depleted placebo (PL) juice (140 mL/day, containing ~0.003 mmol of NO−3) for 3 days. On day 3 of supplementation, subjects cycled at an intensity corresponding to 55% of V̇ O2max for 30 min in hot conditions (30 °C, 50% relative humidity). Chest and forearm sweat rate (SR) and skin blood flow (SkBF), were measured continuously. Cutaneous vascular conductance (CVC) was calculated by SkBF/mean arterial pressure (MAP). Results Prior to exercise, plasma NO− 3 (21±6 and 581±161 µM) and nitrite (NO− 2 , 87±28 and 336±156 nM) concentrations were higher after BR compared to PL supplementation (P≤0.011, n=6). Oesophageal, mean skin, and mean body temperatures during exercise were not different between conditions. In addition, BR supplementation did not affect SR, SkBF, and CVC during exercise. A lower MAP was found after 30 min of exercise following BR supplementation (112±6 and 103±6 mmHg for PL and BR, respectively, P=0.021). Conclusion These results suggest that inorganic NO− 3 supplementation, which increases the potential for O2-independent NO production, does not affect local sweating and cutaneous vascular responses, but attenuates blood pressure in young healthy subjects exercising in a hot environment.

Funding

This study was partly supported by a Grant-in-Aid for Scientific Research (no. 15K14618, 17H02153, and 26882026) from the Japan Society for the Promotion of Science from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.

History

School

  • Sport, Exercise and Health Sciences

Published in

European Journal of Applied Physiology

Citation

AMANO, T. ... et al, 2018. Influence of dietary nitrate supplementation on local sweating and cutaneous vascular responses during exercise in a hot environment. European Journal of Applied Physiology, 118(8), pp. 1579–1588.

Publisher

© Springer

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

10/05/2018

Publication date

2018

Notes

This is a post-peer-review, pre-copyedit version of an article published in European Journal of Applied Physiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00421-018-3889-9.

ISSN

1439-6319

eISSN

1439-6327

Language

en