A randomized sham-controlled trial on the effect of continuous positive airway pressure treatment on gait control in severe obstructive sleep apnea patients.

To determine the effect of continuous positive airway pressure (CPAP), the gold standard treatment for obstructive sleep apnea syndrome (OSAS), on gait control in severe OSAS patients. We conducted a randomized, double-blind, parallel-group, sham-controlled monocentric study in Grenoble Alpes University Hospital, France. Gait parameters were recorded under single and dual-task conditions using a visuo-verbal cognitive task (Stroop test), before and after the 8-week intervention period.

Synergetic Effect of NO Precursor Supplementation and Exercise Training.

Introduction: Nitric oxide (NO) precursor supplementation has been shown to increase NO bioavailability and can potentially improve vascular function and exercise performance. It remains unclear whether the combination of NO precursor supplementation and exercise training has synergic effects on exercise performance. This study aims to assess the effect of chronic nitrate and citrulline intake on exercise training adaptations in healthy young individuals.

Fatigue and Recovery after Single-Stage versus Multistage Ultramarathon Running.

Purpose: Ultramarathon running includes two main types of events: single-stage race (SSR) and multistage races (MSR). Direct comparison of neuromuscular fatigue and recovery after SSR versus MSR race of comparable distance and elevation has never been performed. The aim of this study was to assess neuromuscular fatigue and recovery after two ultramarathons of equal distance performed either (i) in a single stage or (ii) in four successive days.

Effect of chronic nitrate and citrulline supplementation on vascular function and exercise performance in older individuals.

Increased nitric oxide (NO) bioavailability may improve exercise performance and vascular function. It remains unclear whether older adults who experience a decreased NO bioavailability may benefit from chronic NO precursor supplementation. This randomised, double-blind, trial aims to assess the effect of chronic NO precursor intake on vascular function and exercise performance in older adults (60-70 years old).

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 the main finding and its importance? Acute NO precursor ingestion increases the plasma concentrations of NO precursors (nitrate, arginine and citrulline) and enhances post-ischaemic vasodilatation, but has no significant effect on muscle and cerebral oxygenation, peripheral and central mechanisms of neuromuscular fatigue and, consequently, does not improve exercise performance.

Abstract: Nitric oxide (NO) plays an important role in matching blood flow to oxygen demand in the brain and contracting muscles during exercise. Previous studies have shown that increasing NO bioavailability can improve muscle function.

Neuromuscular Dysfunction and Cortical Impairment in Sleep Apnea Syndrome.

Purpose: Lower muscle strength and endurance have been reported in severe obstructive sleep apnea (OSA). Increased intracortical inhibition previously reported at rest in OSA suggests central neuromuscular impairments in these patients. We hypothesized that (i) OSA patients demonstrate reduced knee extensor strength and endurance due to central impairments and (ii) continuous positive airway pressure (CPAP) treatment improves neuromuscular function in these patients.

Effects of Acute Salbutamol Intake on Peripheral and Central Fatigue in Trained Men.

Purpose: Ergogenic effect in physically active subjects has been reported after acute salbutamol (SAL) intake. β2-Agonists have potential stimulant effects within the central nervous system that could be involved in this ergogenic effect. We hypothesized that acute SAL intake would induce changes in cerebral responses during exercise, with significant improvement in cerebral oxygenation and voluntary activation (VA) contributing to an increase in muscle performance.

Effects of high-altitude exposure on supraspinal fatigue and corticospinal excitability and inhibition.

Purpose: While acute hypoxic exposure enhances exercise-induced central fatigue and can alter corticospinal excitability and inhibition, the effect of prolonged hypoxic exposure on these parameters remains to be clarified. We hypothesized that 5 days of altitude exposure would (i) normalize exercise-induced supraspinal fatigue during isolated muscle exercise to sea level (SL) values and (ii) increase corticospinal excitability and inhibition.

Methods: Eleven male subjects performed intermittent isometric elbow flexions at 50% of maximal voluntary contraction to task failure at SL and after 1 (D1) and 5 (D5) days at 4350 m.

Effect of acute nitrate and citrulline supplementation on muscle microvascular response to ischemia-reperfusion in healthy humans.

Nitric oxide (NO) is implicated in vasomotor control mechanisms altering the diameter of the vessels under various physiological and pathological conditions. There are 2 main NO production pathways, 1 NO synthase (NOS) independent (nitrate-nitrite-NO) and the other is NOS dependent (citrulline-arginine-NO). The objective of the study was to evaluate the effect of acute nitrate and citrulline supplementation on post-ischemic vascular response in healthy subjects.

CO2 Clamping, Peripheral and Central Fatigue during Hypoxic Knee Extensions in Men.

Introduction: The central nervous system can play a critical role in limiting exercise performance during hypoxic conditions. Hypocapnia, which is associated with hypoxia-induced hyperventilation, may affect cerebral perfusion. We hypothesized that CO2 clamping during hypoxic isometric knee extensions would improve cerebral oxygenation and reduce central fatigue.