Reduced muscle activation during exercise related to brain oxygenation and metabolism in humans

Muscle oxygenation and pulmonary gas exchange kinetics during cycling exercise on-transitions in humans.

Near-infrared spectroscopy (NIRS) was utilized to gain insights into the kinetics of oxidative metabolism during exercise transitions. Ten untrained young men were tested on a cycle ergometer during transitions from unloaded pedaling to 5 min of constant-load exercise below (VT) the ventilatory threshold. Vastus lateralis oxygenation was determined by NIRS, and pulmonary O2 upta...

Muscle metabolism during fatiguing exercise

In humans af ter short-term maximal exercise muscle glycogen levels are reduced to 75-80% of the initial muscle content. However, data obtained from maximally activated rat muscles show th at after only a few seconds of exercise total glycogen depletion had occurred in many fast fibres . It is argued that during short maximal exercise, effects of glycogen depletion in some fibres may lead to th...

Evaluation of intra-musclar oxygenation during exercise in humans.

Near infrared spectroscopy (NIRS) has been frequently used to assess intra-muscular oxygenation past few decades. In recent years, refinement of NIRS hardware and algorithms used to convert changes in optical absorption to changes in concentration improved the validity of oxygenated haemoglobin (HbO2), deoxyhaemoglobin (Hb), myoglobin (Mb) and the oxidised copper compound of cytochrome aa3 , (c...

Brain oxygenation and metabolism during selective cerebral perfusion in neonates.

OBJECTIVE To investigate the possible neuroprotective effects of selective cerebral perfusion (SCP) during deep hypothermic circulatory arrest on brain oxygenation and metabolism in newborn piglets. METHODS Newborn piglets 2-4 days of age, anesthetized and mechanically ventilated, were used for the study. The animals were placed on cardiopulmonary bypass, cooled to 18 degrees C and put on SCP...

Muscle metabolism during exercise in hemiparetic patients.