The effect of inhaled nitric oxide on maximal oxygen consumption during exercise in acute hypoxia: a randomized double-blind crossover trial.

In moderate hypoxia [partial pressure of inspired oxygen ([Formula: see text]) = 85-111 mmHg], the reduction in maximal oxygen consumption (V̇o) has been attributed to arterial desaturation, whereas in severe hypoxia ([Formula: see text] < 85 mmHg), elevated pulmonary artery pressure (PAP) is thought to impair peak cardiac output ([Formula: see text]) and therefore V̇o. The purpose of this study was to examine whether reducing PAP with inhaled nitric oxide (iNO, a selective pulmonary vasodilator) would increase V̇o in moderate and severe acute hypoxia. Twelve young, healthy participants (mean V̇o = 45.

Reply to: "Ventilatory efficiency in athletes, asthma and obesity": different ventilatory phenotypes during exercise in obesity?

https://bit.ly/3Gl6rHW

Blood glucose concentration is unchanged during exposure to acute normobaric hypoxia in healthy humans.

Normal blood [glucose] regulation is critical to support metabolism, particularly in contexts of metabolic stressors (e.g., exercise, high altitude hypoxia).

Ventilatory efficiency in athletes, asthma and obesity.

During submaximal exercise, minute ventilation ( ) increases in proportion to metabolic rate ( carbon dioxide production ( )) to maintain arterial blood gas homeostasis. The ratio / , commonly termed ventilatory efficiency, is a useful tool to evaluate exercise responses in healthy individuals and patients with chronic disease. Emerging research has shown abnormal ventilatory responses to exercise (either elevated or blunted / ) in some chronic respiratory and cardiovascular conditions.

The effects of high altitude ascent on splenic contraction and the diving response during voluntary apnoea.

New Findings: What is the central question of this study? What is the relative contribution of a putative tonic splenic contraction to the haematological acclimatization process during high altitude ascent in native lowlanders? What is the main finding and its importance? Spleen volume decreased by -14.3% (-15.2 ml) per 1000 m ascent, with an attenuated apnoea-induced [Hb] increase, attesting to a tonic splenic contraction during high altitude ascent.

Cardiorespiratory hysteresis during incremental high-altitude ascent-descent quantifies the magnitude of ventilatory acclimatization.

New Findings: What is the central question of this study? We assessed the utility of a new metric for quantifying ventilatory acclimatization to high altitude, derived from differential ascent and descent steady-state cardiorespiratory variables (i.e. hysteresis).