Acute L-Citrulline Supplementation Increases Nitric Oxide Bioavailability but Not Inspiratory Muscle Oxygenation and Respiratory Performance

The present study aimed to investigate whether acute L-citrulline supplementation would affect inspiratory muscle oxygenation and respiratory performance. Twelve healthy males received 6 g of L-citrulline or placebo in a double-blind crossover …

Circulating biomarkers of nitric oxide bioactivity and impaired muscle vasoreactivity to exercise in adults with uncomplicated type 1 diabetes

Aims/hypothesis: Early compromised endothelial function challenges the ability of individuals with type 1 diabetes to perform normal physical exercise. The exact mechanisms underlying this vascular limitation remain unknown, but may involve either …

Effect of dark chocolate supplementation on tissue oxygenation, metabolism, and performance in trained cyclists at altitude

Dark chocolate (DC) is high in flavonoids and has been shown to increase nitric oxide in the blood. Increased nitric oxide has the potential to improve delivery of oxygen to muscle, especially in hypoxic conditions, such as altitude. Our aim was to …

Effect of acute nitrite infusion on contractile economy and metabolism in isolated skeletal muscle in situ during hypoxia

Key points: Increased plasma nitrite concentrations may have beneficial effects on skeletal muscle function. The physiological basis explaining these observations has not been clearly defined and it may involve positive effects on muscle contraction …

The impact of beetroot juice intake on muscle oxygenation and performance during rhythmic handgrip exercise

Background: Despite studies investigating the effect of beetroot juice (BJ) ingestion on exercise performance in several modes of exercise, it is important to evaluate how untrained subjects respond to BJ intake during fatiguing resistance exercise. …

Plasma asymmetric dimethylarginine concentrations are not related to differences in maximal oxygen uptake in endurance trained and untrained men

New Findings: What is the central question of this study? Is there an association of plasma concentration of asymmetric dimethylarginine, which is related to exercise capacity in patients with cardiovascular diseases, with oxygen delivery and …

Effects of acute nitric oxide precursor intake on peripheral and central fatigue during knee extensions in healthy men

New Findings: What is the central question of this study? What is the effect of acute NO precursor intake on vascular function, muscle and cerebral oxygenation and peripheral and central neuromuscular fatigue during knee-extension exercise? What is …

Effects of a pre-workout supplement on hyperemia following leg extension resistance exercise to failure with different resistance loads

Background: We sought to determine if a pre-workout supplement (PWS), containing multiple ingredients thought to enhance blood flow, increases hyperemia associated with resistance training compared to placebo (PBO). Given the potential interaction …

Effects of dietary nitrate supplementation on physiological responses, cognitive function, and exercise performance at moderate and very-high simulated altitude

Purpose: Nitric oxide (NO) bioavailability is reduced during acute altitude exposure, contributing toward the decline in physiological and cognitive function in this environment. This study evaluated the effects of nitrate (NO3-) supplementation on …

Dietary nitrate modulates cerebral blood flow parameters and cognitive performance in humans: A double-blind, placebo-controlled, crossover investigation

Nitrate derived from vegetables is consumed as part of a normal diet and is reduced endogenously via nitrite to nitric oxide. It has been shown to improve endothelial function, reduce blood pressure and the oxygen cost of sub-maximal exercise, and …

Effect of inorganic nitrate on exercise capacity in heart failure with preserved ejection fraction

Dr. Background-Inorganic nitrate (NO3-), abundant in certain vegetables, is converted to nitrite by bacteria in the oral cavity. Nitrite can be converted to nitric oxide in the setting of hypoxia. We tested the hypothesis that NO3- supplementation …

Effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance

The aim of this study was to examine the acute supplementation effects of dietary nitrate, caffeine, and their combination on 20-km cycling time trial performance. Using a randomized, counterbalanced, double-blind Latin-square design, 14 competitive …

Middle cerebral O2 delivery during the modified Oxford maneuver increases with sodium nitroprusside and decreases during phenylephrine

The modified Oxford maneuver is the reference standard for assessing arterial baroreflex function. The maneuver comprises a systemic bolus injection of 100 $μ$g sodium nitroprusside (SNP) followed by 150 $μ$g phenylephrine (PE). On the one hand, this …

Dietary nitrate supplementation enhances exercise performance in peripheral arterial disease

Peripheral arterial disease (PAD) results in a failure to adequately supply blood and oxygen (O2) to working tissues and presents as claudication pain during walking. Nitric oxide (NO) bioavailability is essential for vascular health and function. …