Effects of Obesity and Sex on Ventilatory Constraints during a Cardiopulmonary Exercise Test in Children.

Purpose: Ventilatory constraints are common during exercise in children, but the effects of obesity and sex are unclear. The purpose of this study was to investigate the effects of obesity and sex on ventilatory constraints (i.e.

Body composition in early pubescent children with obesity: effects following 1 year of nonintervention.

Little is known about whether body composition changes differently between children with and without obesity following 1 year of nonintervention. Therefore, we investigated body composition in early pubescent children (8-12 yr) with and without obesity before and after a period of 1 year of nonintervention. Early pubescent children (8-12 yr; Tanner stage ≤ 3) with (body mass index, BMI ≥ 95th percentile) and without obesity (15th < BMI < 85th percentile) were recruited.

Elevated risk of dyspnea in adults with obesity.

We investigated whether older adults (OA) with obesity are more likely to have dyspnea compared with OA without obesity, and whether OA with obesity are at a greater risk of having dyspnea compared with middle-aged (MA) and younger adults (YA) with obesity. We obtained de-identified data from the TriNetX UT Southwestern Medical Center database. We identified obesity and dyspnea using ICD-10-CM codes E66 and R06.

Inhibiting regional sweat evaporation modifies the ventilatory response to exercise: interactions between core and skin temperature.

In humans, elevated body temperatures can markedly increase the ventilatory response to exercise. However, the impact of changing the effective body surface area (BSA) for sweat evaporation (BSA) on such responses is unclear. Ten healthy adults (9 males, 1 female) performed eight exercise trials cycling at 6 W/kg of metabolic heat production for 60 min.

Six Months of Exercise Training Improves Ventilatory Responses during Exercise in Adults with Well-Healed Burn Injuries.

Introduction: Pulmonary function is lower after a severe burn injury, which could influence ventilatory responses during exercise. It is unclear whether exercise training improves pulmonary function or ventilatory responses during exercise in adults with well-healed burn injuries. Therefore, we tested the hypothesis that exercise training improves pulmonary function and ventilatory responses during exercise in adults with well-healed burn injuries.

Mechanical effects of obesity on central and peripheral airway resistance in nonasthmatic early pubescent children.

Background: In children, obesity typically reduces functional residual capacity (FRC), which reduces airway caliber and increases airway resistance. Whether these obesity-related changes in respiratory function can alter bronchodilator responsiveness is unknown.

Objective: To investigate bronchodilator responsiveness in nonasthmatic children with and without obesity.

Adults with well-healed burn injuries have lower pulmonary function values decades after injury.

Sub-acute (e.g., inhalation injury) and/or acute insults sustained during a severe burn injury impairs pulmonary function.

Dysanapsis in men and women with obesity.

Obesity alters chest wall mechanics, reduces lung volumes, and increases airway resistance. In addition, the luminal area of the larger conducting airways is smaller in women than in men when matched for lung size. We examined whether differences in pulmonary mechanics with obesity and sex were associated with the dysanapsis ratio (DR), an estimate of airway size when the expiratory flow is maximal, in men and women with and without obesity.

Dyspnea during exercise and voluntary hyperpnea in women with obesity.

Temporal responses of ratings of perceived breathlessness (RBP) during constant-load and incremental exercise, and during voluntary hyperpnea (EVH) were examined in women with obesity. Following 6 min of constant-load (60W) cycling, 34 women rated RPB≥4 (+DOE) and 22 women rated RPB≤2 (-DOE). Both groups completed an incremental cycling test and an EVH test at 40 and 60L/min; RPB was assessed each minute of incremental cycling and at the end of each EVH trial.

Inhaled albuterol increases estimated ventilatory capacity in nonasthmatic children without and with obesity.

Forced mid-expiratory flow (i.e., isoFEF) may increase with a short-acting β-agonist in nonasthmatic children without bronchodilator responsiveness.

Pitfalls in Expiratory Flow Limitation Assessment at Peak Exercise in Children: Role of Thoracic Gas Compression.

Purpose: Thoracic gas compression and exercise-induced bronchodilation can influence the assessment of expiratory flow limitation (EFL) during cardiopulmonary exercise tests. The purpose of this study was to examine the effect of thoracic gas compression and exercise-induced bronchodilation on the assessment of EFL in children with and without obesity.

Methods: Forty children (10.

External dead space explains sex-differences in the ventilatory response to submaximal exercise in children with and without obesity.

We compared the exercise ventilatory response (slope of the ventilation, V̇ and carbon dioxide production, V̇CO relationship) in boys and girls with and without obesity. 46 children with obesity (BMI percentile: 97.7 ± 1.

"Train-High Sleep-Low" Dietary Periodization Does Not Alter Ventilatory Strategies During Cycling Exercise.

The purpose of this study was to investigate the effects of "train-high sleep-low" (THSL) dietary periodization on ventilatory strategies during cycling exercise at submaximal and maximal intensities. In a randomized crossover design, 8 trained men [age (mean ± SEM) = 28 ± 1 y; peak oxygen uptake = 56.8 ± 2.

Comparison between a facemask and mouthpiece on breathing mechanics and gas exchange variables during high-intensity exercise.

Gas-collection masks are used as a comfortable alternative to the traditional mouthpiece and noseclip during exercise testing protocols in human performance laboratories. However, these masks may introduce potential problems which could affect metabolic and ventilatory parameters, including gas leaks and added dead space. Therefore, the purpose of this study was to compare breathing mechanics, gas exchange variables and ratings of perceived breathlessness (RPB) during high-intensity exercise between a mouthpiece and face mask.

A Clinician Guide to Altitude Training for Optimal Endurance Exercise Performance at Sea Level.

Constantini, Keren, Daniel P. Wilhite, and Robert F. Chapman.

The role of inspiratory muscle training in the management of asthma and exercise-induced bronchoconstriction.

Asthma is a pathological condition comprising of a variety of symptoms which affect the ability to function in daily life. Due to the high prevalence of asthma and associated healthcare costs, it is important to identify low-cost alternatives to traditional pharmacotherapy. One of these low cost alternatives is the use of inspiratory muscle training (IMT), which is a technique aimed at increasing the strength and endurance of the diaphragm and accessory muscles of respiration.

No Change in Running Mechanics With Live High-Train Low Altitude Training in Elite Distance Runners.

Unlabelled: Investigations into ventilatory, metabolic, and hematological changes with altitude training have been completed; however, there is a lack of research exploring potential gait-kinematic changes after altitude training, despite a common complaint of athletes being a lack of leg "turnover" on return from altitude training.

Purpose: To determine if select kinematic variables changed in a group of elite distance runners after 4 wk of altitude training.

Methods: Six elite male distance runners completed a 28-d altitude-training intervention in Flagstaff, AZ (2150 m), following a modified "live high-train low" model, wherein higherintensity runs were performed at lower altitudes (945-1150 m) and low-intensity sessions were completed at higher altitudes (1950-2850 m).

Marine lipid fraction PCSO-524 (lyprinol/omega XL) of the New Zealand green lipped mussel attenuates hyperpnea-induced bronchoconstriction in asthma.

Purpose: Evaluate the effect of the marine lipid fraction of the New Zealand green-lipped mussel (Perna canaliculus) PCSO-524 (Lyprinol/Omega XL), rich in omega-3 fatty acids, on airway inflammation and the bronchoconstrictor response to eucapnic voluntary hyperpnea (EVH) in asthmatics.

Methods: Twenty asthmatic subjects, with documented HIB, participated in a placebo controlled double-blind randomized crossover trial. Subjects entered the study on their usual diet and were then placed on 3 weeks of PCSO-524 or placebo supplementation, followed by a 2 week washout period, before crossing over to the alternative diet.

Increases in .VO2max with "live high-train low" altitude training: role of ventilatory acclimatization.

The purpose of this study was to estimate the percentage of the increase in whole body maximal oxygen consumption (.VO(2max)) that is accounted for by increased respiratory muscle oxygen uptake after altitude training. Six elite male distance runners (.

Ground contact time as an indicator of metabolic cost in elite distance runners.

Unlabelled: Differences in running economy at common speeds have been demonstrated between male and female distance runners, as well as between middle-distance (MD) and long-distance (LD) specialists. Whether measures of foot ground contact time (tc), known to be proportional to the mass-specific cost of locomotion, follows the same running economy relationships in these groups is unknown.

Purpose: This study examined if differences in tc and selected gait kinematic variables exist between elite male and female distance runners, as well as between elite MD and LD specialists, as running speed increases.

Inspiratory muscle training lowers the oxygen cost of voluntary hyperpnea.

The purpose of this study was to determine if inspiratory muscle training (IMT) alters the oxygen cost of breathing (Vo(2RM)) during voluntary hyperpnea. Sixteen male cyclists completed 6 wk of IMT using an inspiratory load of 50% (IMT) or 15% placebo (CON) of maximal inspiratory pressure (Pi(max)). Prior to training, a maximal incremental cycle ergometer test was performed to determine Vo(2) and ventilation (V(E)) at multiple workloads.

Adjusting flow-mediated dilation for shear stress stimulus allows demonstration of endothelial dysfunction in a population with moderate cardiovascular risk.

Background/aims: Although normalization of brachial artery flow-mediated dilation (FMD) to individual shear stress (FMD:shear stress ratio) has been proposed to improve this measure of endothelial function, the clinical utility of FMD normalization has not yet been demonstrated. We tested (1) whether following conventional 5-min forearm occlusion, the FMD:shear stress ratio would discriminate a population with moderate cardiovascular risk (MR) from a low-risk (LR) population, and (2) whether the dose-response profile relating shear stress to FMD would be different between the 2 populations.

Methods: Five different magnitudes of reactive hyperemia-induced shear stress were applied to 20 MR and 20 LR subjects by manipulating forearm cuff occlusion duration.

Normalization of flow-mediated dilation to shear stress area under the curve eliminates the impact of variable hyperemic stimulus.

Background: Normalization of brachial artery flow-mediated dilation (FMD) to individual shear stress area under the curve (peak FMD:SSAUC ratio) has recently been proposed as an approach to control for the large inter-subject variability in reactive hyperemia-induced shear stress; however, the adoption of this approach among researchers has been slow. The present study was designed to further examine the efficacy of FMD normalization to shear stress in reducing measurement variability.

Methods: Five different magnitudes of reactive hyperemia-induced shear stress were applied to 20 healthy, physically active young adults (25.