A5064877927- High Altitude and Hypoxia
- Cardiovascular and exercise physiology
- Heart Rate Variability and Autonomic Control
- Neuroscience of respiration and sleep
- Traumatic Brain Injury and Neurovascular Disturbances
- Cardiovascular Function and Risk Factors
- Sports Performance and Training
- Thermoregulation and physiological responses
- Mechanical Circulatory Support Devices
- Travel-related health issues
- Spaceflight effects on biology
- Cardiovascular Effects of Exercise
- Cardiac Arrest and Resuscitation
- Hemodynamic Monitoring and Therapy
- Cardiac Structural Anomalies and Repair
- Cardiovascular Health and Disease Prevention
- Climate Change and Health Impacts
- Blood Pressure and Hypertension Studies
- Sports injuries and prevention
- Pulmonary Hypertension Research and Treatments
- Diet and metabolism studies
- Cerebrospinal fluid and hydrocephalus
- Thermal Regulation in Medicine
- Heart Failure Treatment and Management
- Adipose Tissue and Metabolism
Universität Innsbruck
2018-2025
Institute for Exercise and Environmental Medicine
2013-2025
Texas Health Dallas
2013-2025
The University of Texas Southwestern Medical Center
2015-2025
Institute of Mountain Emergency Medicine
2022-2025
Eurac Research
2022-2025
University of Colorado Anschutz Medical Campus
2023
Parker Hannifin (United States)
2023
Parkview Medical Center
2023
Presbyterian Hospital
2015-2020
Key Points Astronauts have recently been discovered to impaired vision, with a presentation that resembles syndromes of elevated intracranial pressure on Earth. Gravity has profound effect fluid distribution and within the human circulation. In contrast prevailing theory, we observed microgravity reduces central venous pressure. This being said, is not reduced levels in 90 deg seated upright posture Thus, over 24 h zero gravity, brain slightly above Earth, which may explain remodelling eye...
Poor fitness in middle age is a risk factor for heart failure, particularly failure with preserved ejection fraction. The development of fraction likely mediated through increased left ventricular (LV) stiffness, consequence sedentary aging. In prospective, parallel group, randomized controlled trial, we examined the effect 2 years supervised high-intensity exercise training on LV stiffness.Sixty-one (48% male) healthy, sedentary, middle-aged participants (53±5 years) were randomly assigned...
During long-term missions, some astronauts experience structural and functional changes of the eyes brain which resemble signs/symptoms experienced by patients with intracranial hypertension. Weightlessness prevents normal cerebral volume pressure 'unloading' associated upright postures on Earth, may be part ocular pathophysiology. By placing lower body in a negative device (LBNP) that pulls fluid away from cranial compartments, we simulated effects gravity significantly lowered within...
Background— Current-generation left ventricular assist devices provide circulatory support that is minimally or entirely nonpulsatile and are associated with marked increases in muscle sympathetic nerve activity (MSNA), likely through a baroreceptor-mediated pathway. We sought to determine whether the restoration of pulsatile flow modulations pump speed would reduce MSNA arterial baroreceptor reflex. Methods Results— Ten men 3 women (54±14 years) Heartmate II continuous-flow underwent...
Background: Chronotropic incompetence is common in heart failure with preserved ejection fraction (HFpEF) and associated impaired aerobic capacity. We investigated the integrity of cardiac β–receptor responsiveness, an important mechanism involved exertional increases HR, HFpEF control subjects. Methods: Thirteen carefully screened patients 13 senior controls underwent exercise testing graded isoproterenol infusion to quantify β–receptor–mediated HR responses. To limit autonomic neural...
The study was undertaken to determine whether normobaric hypoxia causes elevated brain volume and intracranial pressure in individuals with symptoms consistent acute mountain sickness (AMS).Thirteen males age = (26 (sd 6)) years were exposed (12% O2 ) normoxia (21% ). After 2 10 hours, AMS assessed alongside ventricular venous vessel volumes, cerebral blood flow, regional pressure, using high-resolution magnetic resonance imaging.In normoxia, neither lateral (R(2) 0.07, p 0.40) nor...
Cognitive performance is impaired by hypoxia despite global cerebral oxygen delivery and metabolism being maintained. Using arterial spin labelled (ASL) magnetic resonance imaging, this the first study to show regional reductions in blood flow (CBF) response decreased supply (hypoxia) at 2 h that increased area became more pronounced 10 h. Reductions CBF were seen brain regions typically associated with 'default mode' or 'task negative' network. Regional CBF, vasoconstriction, within default...
Key points Despite growing interest in right ventricular form and function diseased states, there is a paucity of data regarding characteristics – namely contractile lusitropic reserve, as well ventricular‐arterial coupling, the healthy heart during rest, submaximal peak exercise. Pressure‐volume analysis ventricle, invasive cardiopulmonary exercise testing, demonstrates that has enormous with three‐ or fourfold increase all metrics contractility, myocardial energy production utilization....
The aim of this study was to compare the power profile, internal and external workloads, racing performance between U23 professional cyclists varying rider types across 2 editions a multistage race.Nine from Union Cycliste Internationale "Continental Team" (age 20.8 [0.9] y; body mass 71.2 [6.3] kg) 8 (28.1 [3.2] 63.0 [4.6] participated in study. Rider were defined as all-rounders, general classification (GC) riders, domestiques. Data collected during 5-day race split into following 4...
Abstract Acute hypoxia increases pulmonary arterial (PA) pressures, though its effect on right ventricular (RV) function is controversial. The objective of this study was to characterize exertional RV performance during acute hypoxia. Ten healthy participants (34 ± 10 years, 7 males) completed three visits: visits 1 and 2 included non‐invasive normoxic (fraction inspired oxygen () = 0.21) isobaric hypoxic ( 0.12) cardiopulmonary exercise testing (CPET) determine normoxic/hypoxic maximal...
Abstract During acute hypoxic exposure, cerebral blood flow (CBF) increases to compensate for the reduced arterial oxygen content (CaO 2 ). Nevertheless, as exposure extends, both CaO and CBF progressively normalize. Haemoconcentration is primary mechanism underlying restoration may therefore explain, at least in part, normalization. Accordingly, we tested hypothesis that reversing haemoconcentration associated with extended returns towards values observed hypoxia. Twenty‐three healthy...
Abstract Time‐restricted feeding (TRF) and aerobic exercise are lifestyle interventions to prevent or manage different metabolic diseases. How these interact, including the impact of meal timing, is not well understood. The aim this study was examine influence TRF on fat oxidation during exercise, whereby participants performed an 8‐week max ‐training program either in fasted state after a carbohydrate‐based snack. 36 were randomized into three groups. (1) Training sessions state; (2)...
Abstract A reduction in cerebral blood flow (CBF) has been observed during spaceflight and bed rest. We aimed to examine the magnitude regional heterogeneity of decrease CBF rest compared posture changes on Earth. Seventeen participants (age, 29 ± 9 years, 7 females) were studied upright supine over 3 days assessed via duplex ultrasonography internal carotid (ICA) vertebral arteries (VA), transcranial Doppler middle artery (MCAv). Mean arterial pressure (MAP) end‐tidal CO 2 () at all time...
Phase contrast magnetic resonance imaging (PC-MRI) and color-coded duplex ultrasonography (CDUS) are commonly used for measuring cerebral blood flow in the internal carotid (ICA) vertebral arteries. However, agreement between two methods has been controversial. Recent development of high spatial temporal resolution vessel wall edge-detection wall-tracking with CDUS increased accuracy reliability diameter, hence measurement. The aim this study was to compare improved method 3 T PC-MRI...
Background: The purpose of this study was to investigate differences in the power profile derived from training and racing, characteristics across a competitive season relationships between U23 professional cyclists. Methods: Thirty male cyclists (age, 20.0 ± 1.0 years; weight, 68.9 6.9 kg; V˙O2max, 73.7 2.5 mL·kg−1·min−1) participated study. cycling split into pre-, early-, mid- late-season periods. Power data 2, 5, 12 min mean maximum (MMP), critical (CP) (Hours, Total Work, eTRIMP,...
Rationale: Chronic exposure to hypoxia is associated with elevated sympathetic nervous activity and reduced vascular function in lowlanders, Andean highlanders suffering from excessive erythrocytosis (EE); however, the mechanistic link between chronically hypoxia-induced dysfunction has not been determined. Objective: To determine impact of heightened on resistance artery endothelial-dependent dilation (EDD), endothelial-independent dilation, lowlanders without EE. Methods Results: We tested...
What is the central question of this study? Herein, a methodological overview our research team's (Global REACH) latest high altitude expedition to Peru provided. main finding and its importance? The experimental objectives, organization, measurements key cohort data are discussed. select presented in manuscript demonstrate haematological differences between lowlanders Andeans with without excessive erythrocytosis. also that exercise capacity was similar study groups at altitude. forthcoming...
The aim of this study was to investigate changes in the power profile U23 professional cyclists during a competitive season based on maximal mean output (MMP) and derived critical (CP) work capacity above CP (W') obtained training racing.A total 13 highly trained (age = 21.1 [1.2] y, maximum oxygen consumption 73.8 [1.9] mL·kg-1·min-1) participated study. cycling split into pre-season in-season. In-season divided early-, mid-, late-season periods. During pre-season, test completed derive...