Fibromyalgia and Chronic Fatigue Syndromes: A systematic review and meta-analysis of cardiorespiratory fitness and neuromuscular function compared with healthy individuals.

Objective: To determine cardiorespiratory fitness and neuromuscular function of people with CFS and FMS compared to healthy individuals.

Design: Systematic review and meta-analysis.

Data Sources: PubMed, Medline, CINAHL, AMED, Cochrane Central Register of Controlled Trials (CENTRAL), and PEDro from inception to June 2022.

Effect of nitrate supplementation on skeletal muscle motor unit activity during isometric blood flow restriction exercise.

Background: Nitrate (NO) supplementation has been reported to lower motor unit (MU) firing rate (MUFR) during dynamic resistance exercise; however, its impact on MU activity during isometric and ischemic exercise is unknown.

Purpose: To assess the effect of NO supplementation on knee extensor MU activities during brief isometric contractions and a 3 min sustained contraction with blood flow restriction (BFR).

Methods: Sixteen healthy active young adults (six females) completed two trials in a randomized, double-blind, crossover design.

The association of elevated blood pressure during ischaemic exercise with sport performance in Master athletes with and without morbidity.

Background: An exaggerated exercise blood pressure (BP) is associated with a reduced exercise capacity. However, its connection to physical performance during competition is unknown.

Aim: To examine BP responses to ischaemic handgrip exercise in Master athletes (MA) with and without underlying morbidities and to assess their association with athletic performance during the World Master Track Cycling Championships 2019.

Reduced skeletal muscle endurance and ventilatory efficiency during exercise in adult smokers without airflow obstruction.

Smokers without airflow obstruction have reduced exercise capacity, but the underlying physiological mechanisms are not fully understood. We aimed to compare quadriceps function assessed using nonvolitional measures and ventilatory requirements during exercise, between smokers without airway obstruction and never-smoker controls. Adult smokers ( = 20) and never-smoker controls ( = 16) aged 25-50 yr with normal spirometry, underwent incremental cycle cardiopulmonary exercise testing to exhaustion with measurement of symptoms and dynamic lung volumes.

Mechanisms of orthopnoea in patients with advanced COPD.

Many patients with severe chronic obstructive pulmonary disease (COPD) report an unpleasant respiratory sensation at rest, which is further amplified by adoption of a supine position (orthopnoea). The mechanisms of this acute symptomatic deterioration are poorly understood.Sixteen patients with advanced COPD and a history of orthopnoea and 16 age- and sex-matched healthy controls underwent pulmonary function tests (PFTs) and detailed sensory-mechanical measurements including inspiratory neural drive (IND) assessed by diaphragm electromyography (EMG), oesophageal pressure ( ) and gastric pressure ( ), in both sitting and supine positions.

Inspiratory muscle training reduces diaphragm activation and dyspnea during exercise in COPD.

Among patients with chronic obstructive pulmonary disease (COPD), those with the lowest maximal inspiratory pressures experience greater breathing discomfort (dyspnea) during exercise. In such individuals, inspiratory muscle training (IMT) may be associated with improvement of dyspnea, but the mechanisms for this are poorly understood. Therefore, we aimed to identify physiological mechanisms of improvement in dyspnea and exercise endurance following inspiratory muscle training (IMT) in patients with COPD and low maximal inspiratory pressure (Pi).

Increased respiratory neural drive and work of breathing in exercise-induced laryngeal obstruction.

Exercise-induced laryngeal obstruction (EILO), a phenomenon in which the larynx closes inappropriately during physical activity, is a prevalent cause of exertional dyspnea in young individuals. The physiological ventilatory impact of EILO and its relationship to dyspnea are poorly understood. The objective of this study was to evaluate exercise-related changes in laryngeal aperture on ventilation, pulmonary mechanics, and respiratory neural drive.

Sensory-mechanical effects of a dual bronchodilator and its anticholinergic component in COPD.

This randomized, double-blind, crossover study examined the physiological rationale for using a dual long-acting bronchodilator (umeclidinium/vilanterol (UME/VIL)) versus its muscarinic-antagonist component (UME) as treatment for dyspnea and exercise intolerance in moderate COPD. After each 4-week treatment period, subjects performed pulmonary function and symptom-limited constant-work rate cycling tests with diaphragm electromyogram (EMGdi), esophageal (Pes), gastric (Pga) and transdiaphragmatic (Pdi) pressure measurements. Fourteen subjects completed the study.

Resting Physiological Correlates of Reduced Exercise Capacity in Smokers with Mild Airway Obstruction.

Smokers with minor spirometric abnormalities can experience persistent activity-related dyspnea and exercise intolerance. Additional resting tests can expose heterogeneous physiological abnormalities, but their relevance and association with clinical outcomes remain uncertain. Subjects included sixty-two smokers (≥20 pack-years), with cough and/or dyspnea and minor airway obstruction [forced expiratory volume in one-second (FEV) ≥80% predicted and >5th percentile lower limit of normal (LLN) (i.

Exertional dyspnoea in COPD: the clinical utility of cardiopulmonary exercise testing.

Activity-related dyspnoea is often the most distressing symptom experienced by patients with chronic obstructive pulmonary disease (COPD) and can persist despite comprehensive medical management. It is now clear that dyspnoea during physical activity occurs across the spectrum of disease severity, even in those with mild airway obstruction. Our understanding of the nature and source of dyspnoea is incomplete, but current aetiological concepts emphasise the importance of increased central neural drive to breathe in the setting of a reduced ability of the respiratory system to appropriately respond.

Mechanisms of exertional dyspnoea in symptomatic smokers without COPD.

Dyspnoea and activity limitation can occur in smokers who do not meet spirometric criteria for chronic obstructive pulmonary disease (COPD) but the underlying mechanisms are unknown.Detailed pulmonary function tests and sensory-mechanical relationships during incremental exercise with respiratory pressure measurements and diaphragmatic electromyography (EMGdi) were compared in 20 smokers without spirometric COPD and 20 age-matched healthy controls.Smokers (mean±sd post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity 75±4%, mean±sd FEV1 104±14% predicted) had greater activity-related dyspnoea, poorer health status and lower physical activity than controls.

Common Mechanisms of Dyspnea in Chronic Interstitial and Obstructive Lung Disorders.

Rationale: The mechanisms underlying dyspnea in interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD) are unknown.

Objectives: To examine whether the relationship between inspiratory neural drive to the diaphragm and exertional dyspnea intensity is different in ILD and COPD, given the marked differences in static respiratory mechanics between these conditions.

Methods: We compared sensory-mechanical relationships in patients with ILD, patients with COPD, and healthy control subjects (n = 16 each) during incremental cycle exercise with diaphragmatic electromyography (EMGdi) and respiratory pressure measurements.

Effective Bronchoscopic Lung Volume Reduction Accelerates Exercise Oxygen Uptake Kinetics in Emphysema.

Background: The impact of bronchoscopic lung volume reduction (BLVR) on physiologic responses to exercise in patients with advanced emphysema remains incompletely understood. We hypothesized that effective BLVR (e-BLVR), defined as a reduction in residual volume > 350 mL, would improve cardiovascular responses to exercise and accelerate oxygen uptake (Vo₂) kinetics.

Methods: Thirty-one patients (FEV1, 36% ± 9% predicted; residual volume, 219% ± 57% predicted) underwent a constant intensity exercise test at 70% peak work rate to the limit of tolerance before and after treatment bronchoscopy (n = 24) or sham bronchoscopy (n = 7).

Effect of age-related ventilatory inefficiency on respiratory sensation during exercise.

To examine the effect of age-related respiratory function impairment on exertional dyspnea, we compared ventilatory and perceptual responses to incremental exercise under control (CTRL) and added dead space (DS) loading conditions in healthy fit older (55-79 years) and younger (20-39 years) men. Older individuals had higher ventilatory equivalents for CO2 throughout exercise (p<0.05) suggesting greater ventilatory inefficiency but operating lung volumes were similar compared to younger individuals.

On the method of fitting cardiac output kinetics in severe exercise.

The kinetic responses of oxygen uptake (VO₂) and cardiac output (Q) describe the rate at which these physiological variables approach the required steady state value with work rate transitions. In this issue of the Journal, Adami and colleagues examined the kinetic responses during the transition to severe intensity exercise (metabolic demands exceeding maximal VO₂). Two methods were described for fitting VO₂ kinetics: one was an exponential model that referenced the time course of VO₂ relative to an apparent plateau while the second examined the rate of change with respect to the value predicted to be 120% of maximal VO₂.

O2 uptake and blood pressure regulation at the onset of exercise: interaction of circadian rhythm and priming exercise.

Circadian rhythm has an influence on several physiological functions that contribute to athletic performance. We tested the hypothesis that circadian rhythm would affect blood pressure (BP) responses but not O(2) uptake (Vo(2)) kinetics during the transitions to moderate and heavy cycling exercises. Nine male athletes (peak Vo(2): 60.

Prolonged ischaemia impairs muscle blood flow and oxygen uptake dynamics during subsequent heavy exercise.

Muscle oxygen uptake ( ˙VO₂,mus) dynamics at the onset of exercise can be affected by prior heavy exercise.We tested the hypothesis that elevated forearm blood flow (FBF) following prior circulatory occlusion would also be associated with accelerated ˙VO₂,mus dynamics during subsequent heavy hand-grip exercise. Ten trained young men performed 5 min of heavy hand-grip exercise at 30% MVC as a control (CON), and four additional heavy bouts after brief recovery from: (1) prior heavy exercise (Heavy A), (2) heavy exercise followed by 2 min occlusion (Heavy B), (3) 15 min occlusion (Heavy C), and (4) 5 min occlusion with 1 min of moderate exercise during occlusion (Heavy D).

Prior moderate and heavy exercise accelerate oxygen uptake and cardiac output kinetics in endurance athletes.

Cardiorespiratory interactions at the onset of dynamic cycling exercise are modified by warm-up exercises. We tested the hypotheses that oxygen uptake (Vo(2)) and cardiac output (Q) kinetics would be accelerated at the onset of heavy and moderate cycling exercise by warm-up. Nine male endurance athletes (peak Vo(2): 60.