Dietary nitrate reduces muscle metabolic perturbation and improves exercise tolerance in hypoxia

<jats:p><jats:bold>Non‐Technical Summary </jats:bold> Reduced atmospheric O<jats:sub>2</jats:sub> availability (hypoxia) impairs muscle oxidative energy production and exercise tolerance. We show that dietary supplementation with inorganic nitrate reduces markers of muscle fatigue and improves high‐intensity exercise tolerance in healthy adults inhaling air containing 14.5% O<jats:sub>2</jats:sub>. In the body, nitrate can be converted to nitrite and nitric oxide. These molecules can improve muscle efficiency and also dilate blood vessels allowing more O<jats:sub>2</jats:sub> to be delivered to active muscle. These results suggest that dietary nitrate could be beneficial during exercise at moderate to high altitude and in conditions where O<jats:sub>2</jats:sub> delivery to muscle is reduced such as in pulmonary, cardiovascular and sleep disorders.</jats:p>