Peripheral impairments of oxidative metabolism after a 10-day bed rest are upstream of mitochondrial respiration

In order to identify peripheral biomarkers of impaired oxidative metabolism during exercise following a 10-day bed rest, 10 males performed an incremental exercise (to determine peak pulmonary V˙O 2 (V˙O 2 p)) and moderate-intensity exercises, before …

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 …

Test–retest reliability of pulmonary oxygen uptake and muscle deoxygenation during moderate- and heavy-intensity cycling in youth elite-cyclists

To establish the test–retest reliability of pulmonary oxygen uptake (V̇O2), muscle deoxygenation (deoxy[haem]) and tissue oxygen saturation (StO2) kinetics in youth elite-cyclists. From baseline pedalling, 15 youth cyclists completed 6-min step …

In vivo assessment of muscle mitochondrial function in healthy, young males in relation to parameters of aerobic fitness

Purpose: The recovery of muscle oxygen consumption (mV˙ O2) after exercise provides a measure of skeletal muscle mitochondrial capacity, as more and better-functioning mitochondria will be able to restore mV˙ O2 faster to the pre-exercise state. The …

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 …

Activity-induced changes in skeletal muscle metabolism measured with optical spectroscopy

PURPOSE: Previous studies have used near-infrared spectroscopy (NIRS) to measure skeletal muscle mitochondrial capacity. This study tested the hypothesis that NIRS-measured mitochondrial capacity would improve with endurance exercise training and …

Noninvasive evaluation of skeletal muscle mitochondrial capacity with near-infrared spectroscopy: Correcting for blood volume changes

Near-infrared spectroscopy (NIRS) is a well-known method used to measure muscle oxygenation and hemodynamics in vivo. The application of arterial occlusions allows for the assessment of muscle oxygen consumption (mVO 2) using NIRS. The aim of this …

A prior bout of contractions speeds V̇o2 and blood flow on-kinetics and reduces the V̇o2 slow-component amplitude in canine skeletal muscle contracting in situ

It was the purpose of this study to examine the effect of a priming contractile bout on oxygen, uptake (V̇o2) on-kinetics in highly oxidative skeletal muscle. Canine gastrocnemii (n = 12) were stimulated via their sciatic nerves (8 V, 0.2-ms …