A5024289844- Cardiovascular and exercise physiology
- Chronic Obstructive Pulmonary Disease (COPD) Research
- Sports Performance and Training
- Heart Rate Variability and Autonomic Control
- Cardiovascular Effects of Exercise
- Muscle activation and electromyography studies
- Respiratory Support and Mechanisms
- Muscle metabolism and nutrition
- Asthma and respiratory diseases
- Pulmonary Hypertension Research and Treatments
- Cardiovascular Function and Risk Factors
- Adipose Tissue and Metabolism
- Nutrition and Health in Aging
- Exercise and Physiological Responses
- Advanced MRI Techniques and Applications
- Mitochondrial Function and Pathology
- High Altitude and Hypoxia
- Physical Activity and Health
- Muscle Physiology and Disorders
- Hemodynamic Monitoring and Therapy
- Interstitial Lung Diseases and Idiopathic Pulmonary Fibrosis
- Neuroscience of respiration and sleep
- Non-Invasive Vital Sign Monitoring
- Extracellular vesicles in disease
- Health and Wellbeing Research
UCLA Medical Center
2016-2025
Harbor–UCLA Medical Center
2016-2025
The Lundquist Institute
2013-2024
Los Angeles Medical Center
2012-2024
NIHR Leicester Biomedical Research Centre
2023
American College of Sports Medicine
2023
Liverpool Hope University
2015-2022
Vrije Universiteit Amsterdam
2022
University of Pavia
2022
University of Leeds
2012-2021
1. The maximal oxygen uptake (V(O(2),peak)) during dynamic muscular exercise is commonly taken as a crucial determinant of the ability to sustain high-intensity exercise. Considerably less attention, however, has been given rate at which V(O(2)) increases attain this maximum (or its submaximal requirement), and even kinetic features response following 2. Six, healthy, male volunteers (aged 22 58 years), each performed 13 tests: initial ramp-incremental cycle ergometry limit tolerance...
The quantification of maximum oxygen uptake (V̇o 2 max ), a parameter characterizing the effective integration neural, cardiopulmonary, and metabolic systems, requires ) to attain plateau. We were interested in whether V̇o plateau was consistently manifest during maximal incremental ramp cycle ergometry also ascertaining relationship between this peak that determined from one, or several, constant-load tests. Ventilatory pulmonary gas-exchange variables measured breath by with turbine mass...
Rationale: The small conducting airways are the major site of airflow obstruction in chronic obstructive pulmonary disease and may precede emphysema development.Objectives: We hypothesized a novel computed tomography (CT) biomarker airway predicts FEV1 decline.Methods: analyzed 1,508 current former smokers from COPDGene with linear regression to assess predictors change (ml/yr) over 5 years. Separate models for subjects without were generated using baseline clinical physiologic addition two...
Abstract The accumulation of dysfunctional mitochondria has been implicated in aging, but a deeper understanding mitochondrial dynamics and mitophagy during aging is missing. Here, we show that upregulating Drp1—a Dynamin-related protein promotes fission—in midlife, prolongs Drosophila lifespan healthspan. We find short-term induction Drp1, sufficient to improve organismal health prolong lifespan, observe midlife shift toward more elongated morphology, which linked the aged flight muscle....
Abstract The anaerobic threshold (AT) remains a widely recognized, and contentious, concept in exercise physiology medicine. As conceived by Karlman Wasserman, the AT coalesced increase of blood lactate concentration ([La − ]), during progressive test, with an excess pulmonary carbon dioxide output ( ). Its principal tenets were: limiting oxygen (O 2 ) delivery to exercising muscle→increased glycolysis, La H + production→decreased muscle pH→with increased buffered [HCO 3 ]→increased CO...
Chronic obstructive pulmonary disease (COPD) remains a major cause of morbidity and mortality. Present-day diagnostic criteria are largely based solely on spirometric criteria. Accumulating evidence has identified substantial number individuals without COPD who suffer from respiratory symptoms and/or increased There is clear need for an expanded definition that linked to physiologic, structural (computed tomography [CT]) clinical disease. Using data the Genetic Epidemiology study (COPDGene
Recent respiratory outbreaks have garnered substantial attention, yet most monitoring remains confined to physical signals. Exhaled breath condensate (EBC) harbors rich molecular information that could unveil diverse insights into an individual’s health. Unfortunately, challenges related sample collection and the lack of on-site analytical tools impede widespread adoption EBC analysis. Here, we introduce EBCare, a mask-based device for real-time in situ biomarkers. Using tandem cooling...
The on‐ and off‐transient (i.e. phase II) responses of pulmonary oxygen uptake (V̇ O2 ) to moderate‐intensity exercise below the lactate threshold, θ L in humans has been shown conform both mono‐exponentiality ‘on‐off’ symmetry, consistent with a system manifesting linear control dynamics. However above V̇ kinetics have be more complex: during high‐intensity neither nor symmetry appropriately characterise response. Muscle [phosphocreatine] ([PCr]) exercise, however, proposed dynamically...
1. In the non-steady state of moderate intensity exercise, pulmonary O2 uptake (Vp,O2) is temporally dissociated from muscle consumption (Vm,O2) due to influence intervening venous blood volume and contribution body stores ATP synthesis. A monoexponential model Vp,O2 without a delay term, therefore, implies an obligatory slowing kinetics in comparison Vm, O2. 2. During association Vm,O2 [phosphocreatine] ([PCr]) necessary consequence control muscular oxidative phosphorylation mediated by...
The O 2 uptake (V̇o ) response to ramp incremental (RI) exercise does not consistently demonstrate plateau-like behavior at the limit of tolerance, and hence requirements for a maximum V̇o commonly are met, despite apparent effort. We sought determine whether an appended step (SE) test work rate greater than that achieved in preceding would establish plateau criterion. Seven healthy male adults performed RI cycle ergometry (20 W/min) followed by 5-min recovery W) then SE 105% (RISE-105)...
To test the hypothesis that VEGF is important for maintenance of alveolar structure and elastic properties in adult mice, lung-targeted ablation gene was accomplished through intratracheal delivery an adeno-associated cre recombinase virus (AAV/Cre) to VEGFloxP effects were followed 8 wk. Control mice similarly treated with AAV/Cre. Pulmonary levels reduced by 86% at 5 wk postinfection but returned normal receptor VEGFR-2 also (by 51%) control values However, septal wall destruction...
1 A prior bout of high-intensity square-wave exercise can increase the temporal adaptation pulmonary oxygen uptake (V̇O2) to a subsequent exercise. The mechanisms controlling this adaptation, however, are poorly understood. 2 We therefore determined dynamics intramuscular [phosphocreatine] ([PCr]) simultaneously with those V̇O2 in seven males who performed two consecutive bouts square-wave, knee-extensor prone position for 6 min rest interval. magnetic resonance spectroscopy (MRS)...
Tolerance to high-intensity constant-power (P) exercise is well described by a hyperbola with two parameters: curvature constant (W') and power asymptote termed "critical power" (CP). Since the ability sustain closely related meet ATP demand in steady state, we reasoned that pulmonary O(2) uptake (Vo(2)) kinetics would relate P-tolerable duration (t(lim)) parameters. We hypothesized 1) fundamental time (τVo(2)) inversely CP; 2) slow-component magnitude (ΔVo(2sc)) directly W'. Fourteen...
Physical activity (PA) is of key importance for health among healthy persons and individuals with chronic obstructive pulmonary disease (COPD). PA has multiple dimensions that can be assessed quantified objectively using monitors. Moreover, as shown in the published literature, variable methodologies have been used to date quantify COPD, precluding clear comparisons outcomes across studies. The present paper aims provide a summary available literature rationale behind measured proposes...
The dynamics of pulmonary O 2 uptake (V˙o ) during the on-transient high-intensity exercise depart from monoexponentiality as a result “slow component” whose mechanisms remain conjectural. Progressive recruitment glycolytic muscle fibers, with slow utilization kinetics and low efficiency, has, however, been suggested mechanism. demonstration high- low-pH components exercising skeletal 31 P magnetic resonance (MR) spectrum [inorganic phosphate (P i peak] at high work rates (thought to be...
The physiological equivalents of the curvature constant (W') high-intensity power-duration (P-t(LIM)) relationship are poorly understood, although they presumed to reach maxima/minima at exhaustion. In an attempt improve our understanding determinants W', we therefore aimed determine its recovery kinetics following exhaustive exercise (which depletes W') concomitantly with those O(2) uptake (V(O(2)), a proxy for phosphocreatine replenishment) and blood lactate concentration ([L(-)]). Six men...