Boys vs men differences in muscular fatigue, muscle and cerebral oxygenation during maximal effort isometric contractions: the effect of muscle blood flow restriction.

Purpose: To examine whether the children's superiority, over adults, to resist fatigue during repeated maximal-efforts depends on their often-cited oxidative advantage, attributed to greater muscle blood flow and O-delivery. We also investigated the mechanisms underlying child-adult differences in muscle-oxygenation (due to O-supply or O-utilization) and examined if there are age-differences in cerebral-oxygenation response (a brain-activation index).

Methods: Eleven men (23.

Heart rate variability at rest and in response to stress: Comparative study between hemodialysis and peritoneal dialysis patients.

Cardiac arrhythmias and sudden death are the leading causes of mortality in end-stage kidney disease (ESKD). Autonomic nervous system (ANS) dysfunction contributes to this arrhythmogenic background. This study compared heart rate variability (HRV) indices between hemodialysis (HD) and peritoneal dialysis (PD) patients, both at rest and in response to mental and physical stimulation maneuvers.

Cerebral oxygenation during exercise deteriorates with advancing chronic kidney disease.

Background: Cognitive impairment and exercise intolerance are common in chronic kidney disease (CKD). Cerebral perfusion and oxygenation play a major role in both cognitive function and exercise execution. This study aimed to examine cerebral oxygenation during a mild physical stress in patients at different CKD stages and controls without CKD.

NIRS-Derived Muscle-Deoxygenation and Microvascular Reactivity During Occlusion-Reperfusion at Rest Are Associated With Whole-Body Aerobic Fitness.

Near-infrared spectroscopy (NIRS) indices during arterial occlusion-reperfusion maneuver have been used to examine the muscle's oxidative metabolism and microvascular function-important determinants of whole-body aerobic-fitness. The association of NIRS-derived parameters with whole-body VOmax was previously examined using a method requiring exercise (or electrical stimulation) followed by multiple arterial occlusions. We examined whether NIRS-derived indices of muscle deoxygenation and microvascular reactivity assessed during a single occlusion-reperfusion are (a) associated with maximal/submaximal indices of whole-body aerobic-fitness and (b) could discriminate individuals with different VOmax.

Hemodialysis Effects on Autonomic Function: Results of Linear and Nonlinear Analysis of Heart Rate Variability at Rest and in Response to Physical and Mental Stress Tests.

Introduction: Cardiac arrhythmias are the most common cause of death in hemodialysis. Autonomic dysfunction plays a central role in this arrhythmogenic background. Previous studies on hemodialysis-related changes in heart rate variability (HRV) give contradictory results.

Brain oxygenation during multiple sets of isometric and dynamic resistance exercise of equivalent workloads: Association with systemic haemodynamics.

Brain function relies on sufficient blood flow and oxygen supply. Changes in cerebral oxygenation during exercise have been linked to brain activity and central command. Isometric- and dynamic-resistance exercise-(RE) may elicit differential responses in systemic circulation, neural function and metabolism; all important regulators of cerebral circulation.