Recent developments in near-infrared spectroscopy (NIRS) for the assessment of local skeletal muscle microvascular function and capacity to utilise oxygen

Purpose of review Continuous wave near infrared spectroscopy (CW NIRS) provides non-invasive technology to measure relative changes in oxy- and deoxy-haemoglobin in a dynamic environment. This allows determination of local skeletal muscle O2 …

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 …

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 …

Reproducibility of near-infrared spectroscopy measurements of oxidative function and postexercise recovery kinetics in the medial gastrocnemius muscle

The purpose of this study was to assess the reproducibility of resting blood flow, resting oxygen consumption, and mitochondrial capacity in skeletal muscle using near-infrared spectroscopy (NIRS). We also determined the influence of 2 exercise …

AltitudeOmics: Exercise-induced supraspinal fatigue is attenuated in healthy humans after acclimatization to high altitude

Aims: We asked whether acclimatization to chronic hypoxia (CH) attenuates the level of supraspinal fatigue that is observed after locomotor exercise in acute hypoxia (AH). Methods: Seven recreationally active participants performed identical bouts of …

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 …

Use of NIRS to assess effect of training on peripheral muscle oxygenation changes in elite rugby players performing repeated supramaximal cycling tests

In most team sports, intermittent high intensity sprint efforts combined with short recovery periods have been identified as a key factor of physical performance; the ability to repeat these efforts at a sustained level is of great importance. …

Exertional periodic breathing potentiates erythrocyte rheological dysfunction by elevating pro-inflammatory status in patients with anemic heart failure

Background: Exertional periodic breathing (EPB) or anemia is associated with an adverse prognosis in advanced heart failure (HF). The disturbed rheological properties of erythrocytes may contribute to circulatory disorders. This study investigated …

Faster pulmonary oxygen uptake kinetics in children vs adults due to enhancements in oxygen delivery and extraction

This study aimed to examine if the faster pulmonary oxygen uptake (VO2p) phase 2 in children could be explained by increased O 2 availability or extraction at the muscle level. For that purpose, O 2 availability and extraction were assessed using …

Near-infrared spectroscopy during exercise and recovery in children with juvenile dermatomyositis

Introduction: We hypothesized that microvascular disturbances in muscle tissue play a role in the reduced exercise capacity in juvenile dermatomyositis (JDM). Methods: Children with JDM, children with juvenile idiopathic arthritis (clinical …

Peak oxygen uptake and regional oxygenation in response to a 10-day confinement to normobaric hypoxia

We investigated the effect of hypoxic acclimatization per se, without any concomitant influence of strenuous physical activity on muscle and cerebral oxygenation. Eight healthy male subjects participated in a crossover-designed study. In random …

Near-infrared spectroscopy assessment following exercise training in patients with intermittent claudication and in untrained healthy participants

Selected near-infrared spectroscopy (NIRS) parameters were assessed in healthy untrained participants and in peripheral arterial disease (PAD) trained patients to evaluate their usefulness in rehabilitative outcome. Forty-five PAD and 15 healthy …

VO 2 on-kinetics in isolated canine muscle in situ during slowed convective O 2 delivery

The purpose of this study was to examine O 2 uptake (VO 2) on-kinetics when the spontaneous blood flow (and therefore O 2 delivery) onresponse was slowed by 25 and 50 s. The isolated gastrocnemius muscle complex (GS) in situ was studied in six …

Cerebral blood flow and oxygenation at maximal exercise: The effect of clamping carbon dioxide

During exercise, as end-tidal carbon dioxide (PETCO2) drops after the respiratory compensation point (RCP), so does cerebral blood flow velocity (CBFv) and cerebral oxygenation. This low-flow, low-oxygenation state may limit work capacity. We …

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. …

Skeletal muscle metabolic recovery following submaximal exercise in chronic heart failure is limited more by O2 delivery than O2 utilization

CHF (chronic heart failure) is associated with a prolonged recovery of skeletal muscle energy stores following submaximal exercise, limiting the ability to perform repetitive daily activities. However, the pathophysiological background of this …