Docosahexaenoic acid-rich fish oil modulates the cerebral hemodynamic response to cognitive tasks in healthy young adults

A number of recent studies have assessed the impact of dietary omega-3 polyunsaturated fatty acids (n-3 PUFAs) on behavioral outcomes; however, very little attention has been given to their impact upon brain function in physiological terms. …

Muscle contractile properties in patients with repetitive strain injury

Objectives Repetitive strain injury [RSI] is a multi-factorial overuse syndrome that has been associated with local vascular and muscular impairments. Recently, we found vascular changes also in the non-affected site, which is suggestive for systemic …

Oscillations in cerebral blood flow and cortical oxygenation in Alzheimer's disease

In Alzheimer's disease (AD) cerebrovascular function is at risk. Transcranial Doppler, near-infrared spectroscopy, and photoplethysmography are noninvasive methods to continuously measure changes in cerebral blood flow velocity (CBFV), cerebral …

Short intermittent hypoxic exposures augment ventilation but do not alter regional cerebral and muscle oxygenation during hypoxic exercise

This study investigated the effects of four exposures to normobaric hypoxia (SIH group; FIO2=0.120, N= 10) or placebo-control normoxia (Control group; FI O2=0.209, N= 9) on cardio-respiratory responses to hypoxic exercise. Before and after the …

Functional impairment of skeletal muscle oxidative metabolism during knee extension exercise after bed rest

A functional evaluation of skeletal muscle oxidative metabolism during dynamic knee extension (KE) incremental exercises was carried out following a 35-day bed rest (BR) (Valdoltra 2008 BR campaign). Nine young male volunteers (age: 23.5 ± 2.2 yr; …

The use of near-infrared spectroscopy in understanding skeletal muscle physiology: Recent developments

This article provides a snapshot of muscle near-infrared spectroscopy (NIRS) at the end of 2010 summarizing the recent literature, offering the present status and perspectives of the NIRS instrumentation and methods, describing the main NIRS studies …

Assessing running economy during field running with changes of direction: Application to 20 m shuttle runs

Purpose: To examine physiological responses to submaximal field running with changes of direction (COD), and to compare two approaches to assess running economy (RE) with COD, ie, during square-wave (SW) and incremental (INC) exercises. Methods: Ten …

Cerebral blood flow and behavioural effects of caffeine in habitual and non-habitual consumers of caffeine: A near infrared spectroscopy study

Caffeine has been shown to modulate cerebral blood flow, with little evidence of tolerance to these effects following habitual use. However, previous studies have focused on caffeine levels much higher than those found in dietary servings and have …

Quantitative analysis of hemodynamic and metabolic changes in subcortical vascular dementia using simultaneous near-infrared spectroscopy and fMRI measurements

Subcortical vascular dementia (SVD) is a form of vascular dementia from small vessel disease with white matter lesions and lacunes. We hypothesized that hemodynamic and metabolic changes in the cortex during a simple motor task may reflect the …

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 …

Does cerebral oxygen delivery limit incremental exercise performance?

Previous studies have suggested that a reduction in cerebral oxygen delivery may limit motor drive, particularly in hypoxic conditions, where oxygen transport is impaired. We hypothesized that raising end-tidal PCO 2 (PETCO 2) during incremental …

Effect of endurance training on performance and muscle reoxygenation rate during repeated-sprint running

The aim of the present study was to examine the effect of an 8-week endurance training program on repeated-sprint (RS) performance and post-sprints muscle reoxygenation rate in 18 moderately trained males (34 ± 5 years). Maximal aerobic speed (MAS), …

Effects of aging on the cerebrovascular orthostatic response

When healthy subjects stand up, it is associated with a reduction in cerebral blood velocity and oxygenation although cerebral autoregulation would be considered to prevent a decrease in cerebral perfusion. Aging is associated with a higher incidence …

Performance and physiological responses to repeated-sprint and jump sequences

In this study, the performance and selected physiological responses to team-sport specific repeated-sprint and jump sequence were investigated. On four occasions, 13 team-sport players (22 ± 3 year) performed alternatively six repeated maximal …

Cerebral oxygenation decreases but does not impair performance during self-paced, strenuous exercise

Aim: The reduction in cerebral oxygenation (Cox) is associated with the cessation of exercise during constant work rate and incremental tests to exhaustion. Yet in exercises of this nature, ecological validity is limited due to work rate being either …

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 …

Cortical oxygen supply during postural hypotension is further decreased in Alzheimer's disease, but unrelated to cholinesterase-inhibitor use

Cerebrovascular function and structure of the cortical cerebral microvessels are profoundly altered in patients with Alzheimer's disease (AD). The functional hemodynamic consequences of such changes, however, remain essentially unknown. …

Muscle tissue oxygenation and VEGF in VO2-matched vibration and squatting exercise

Summary: Exposure to vibration has traditionally been associated with compromised perfusion. This study investigated whether blood supply during whole body vibration (WBV), as an exercise modality, is in proportion to the metabolic demand by the …

Physiological responses to shuttle repeated-sprint running

This study investigated the influence of 180° changes of direction during a repeated-sprint running test on performance, cardiorespiratory variables, muscle deoxygenation and post-exercise blood lactate ([La] levels. Thirteen team-sport athletes …

Resting muscle oxygen consumption by near-infrared spectroscopy in peripheral arterial disease: A parameter to be considered in a clinical setting?

Resting muscle VO2 consumption (rmVO2) as measured by near-infrared spectroscopy (NIRS) has been poorly studied in peripheral arterial disease (PAD). We studied the feasibility of its assessment in a clinical setting, compared values from PAD and …