Cardiovascular and metabolic responses to passive hypoxic conditioning in overweight and mildly obese individuals

Although severe intermittent hypoxi Although severe intermittent hypoxia (IH) is well known to induce deleterious cardiometabolic consequences, moderate IH may induce positive effects in obese individuals. The present study aimed to evaluate the …

Cerebral and Muscle Oxygenation during Repeated Shuttle Run Sprints with Hypoventilation

Ten highly-trained Jiu-Jitsu fighters performed 2 repeated-sprint sessions, each including 2 sets of 8 x $∼$6 s back-and-forth running sprints on a tatami. One session was carried out with normal breathing (RSN) and the other with voluntary …

Chronic high-dose beetroot juice supplementation improves time trial performance of well-trained cyclists in normoxia and hypoxia

Dietary nitrate (NO 3− ) supplementation via beetroot juice (BR) is known to improve endurance performance in untrained and moderately trained individuals. However, conflicting results exist in well-trained individuals. Evidence suggests that the …

Physiological adaptations to repeated sprint training in hypoxia induced by voluntary hypoventilation at low lung volume

Purpose: This study investigated the effects of repeated-sprint (RS) training in hypoxia induced by voluntary hypoventilation at low lung volume (RSH-VHL) on physiological adaptations, RS ability (RSA) and anaerobic performance. Methods: Over a …

The effect of zolpidem on cognitive function and postural control at high altitude

Study Objectives Sleep is altered at high altitude leading many mountaineers to use hypnotics in order to improve sleep efficiency. While after a full night at altitude the short-acting hypnotic zolpidem does not appear to alter cognitive function, …

Oral nitrate supplementation differentially modulates cerebral artery blood velocity and prefrontal tissue oxygenation during 15 km time-trial cycling in normoxia but not in hypoxia

Background: Nitrate is a precursor of nitric oxide (NO), an important regulator of cerebral perfusion in normoxic and hypoxic conditions. Nitrate supplementation could be used to improve cerebral perfusion and oxygenation during exercise in hypoxia. …

Acute effects of repeated cycling sprints in hypoxia induced by voluntary hypoventilation

Purpose: This study aimed to investigate the acute responses to repeated-sprint exercise (RSE) in hypoxia induced by voluntary hypoventilation at low lung volume (VHL). Methods: Nine well-trained subjects performed two sets of eight 6-s sprints on a …

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 …

Oxygen delivery is not a limiting factor during post-exercise recovery in healthy young adults

Purpose It is still equivocal whether oxygen uptake recovery kinetics are limited by oxygen delivery and can be improved by supplementary oxygen. The present study aimed to investigate whether measurements of muscle and pulmonary oxygen uptake …

Effect of ageing on hypoxic exercise cardiorespiratory, muscle and cerebral oxygenation responses in healthy humans

New Findings: What is the central question of this study? This study aimed to determine the effect of ageing on cardiorespiratory and tissue oxygenation responses to hypoxia during maximal incremental exercise. What is the main finding and its …

Effect of hypoxia on cerebrovascular and cognitive function during moderate intensity exercise

Exercise in hypoxia places added demands on the brain and cerebrovasculature that can impact cognitive function. The purpose of this study was to investigate the effect of acute hypoxia on cerebrovascular hemodynamics, markers of neuro-steroidal …

Physiological characteristics of elite high-altitude climbers

Factors underlying the amplitude of exercise performance reduction at altitude and the development of high-altitude illnesses are not completely understood. To better describe these mechanisms, we assessed cardiorespiratory and tissue oxygenation …

High-intensity Interval training enhances mobilization/functionality of endothelial progenitor cells and depressed shedding of vascular endothelial cells undergoing hypoxia

Purpose: Exercise training improves endothelium-dependent vasodilation, whereas hypoxic stress causes vascular endothelial dysfunction. Monocyte-derived endothelial progenitor cells (Mon-EPCs) contribute to vascular repair process by differentiating …

Separate and combined effects of a 10-d exposure to hypoxia and inactivity on oxidative function in vivo and mitochondrial respiration ex vivo in humans

An integrative evaluation of oxidative metabolism was carried out in 9 healthy young men (age, 24.1 1.7 yr mean=SD) before (CTRL) and after a 10-day horizontal bed rest carried out in normoxia (N-BR) or hypoxia (H-BR, FIO2 0.147). H-BR was designed …

Repeated apnea-induced contraction of the spleen in cyclists does not enhance performance in a subsequent time-trial

Purpose: Splenic contraction induced by repeated apneas has been shown to increase oxygen availability. Our aim was to determine whether repeated maximal voluntary apnea enhances the performance of cyclists in a subsequent 4-km time trial. Methods: …

Cerebral oxygenation during the Richalet hypoxia sensitivity test and cycling time-trial performance in severe hypoxia

Background: The Richalet hypoxia sensitivity test (RT), which quantifies the cardiorespiratory response to acute hypoxia during exercise at an intensity corresponding to a heart rate of $∼$130 bpm in normoxia, can predict susceptibility of altitude …

Repeated pre-syncope from increased inspired co2 in a background of severe hypoxia

We describe a case of experimentally induced pre-syncope in a healthy young man when exposed to increased inspired CO2 in a background of hypoxia. Acute severe hypoxia (FIO2=0.10) was tolerated, but adding CO2 to the inspirate caused pre-syncope …

Hypoxic exercise training improves cardiac/muscular hemodynamics and is associated with modulated circulating progenitor cells in sedentary men

Background Circulating progenitor cells (CPCs) improve cardiovascular function and organ perfusion by enhancing the capacities of endothelial repair and neovasculogenesis. This study investigates whether exercise regimens with/without hypoxia affect …

Peripheral fatigue is not critically regulated during maximal, intermittent, dynamic leg extensions

Central motor drive to active muscles is believed to be reduced during numerous exercise tasks to prevent excessive peripheral fatigue development. The purpose of the present study was to use hypoxia to exacerbate physiological perturbations during a …

Carbon monoxide exposure during exercise performance: Muscle and cerebral oxygenation

Aim: To investigate the effect of carbon monoxide (CO) in the inspired air as anticipated during peak hours of traffic in polluted megalopolises on cerebral, respiratory and leg muscle oxygenation during a constant-power test (CPT). In addition, …