Louis Laviolette

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BACKGROUND Identification of the physiologic factors most relevant to functional independence in the elderly population is critical for the design of effective interventions. It has been suggested that muscle power may be more directly related to impaired physical performance than muscle strength in elderly persons. We tested the hypothesis that peak muscle(More)
BACKGROUND The optimal way of assessing the impact of pulmonary rehabilitation on functional status in chronic obstructive pulmonary disease (COPD) is currently unknown. The minimal clinically important difference for the constant work rate cycling exercise test also needs to be investigated to facilitate its interpretation. A study was undertaken to(More)
BACKGROUND We examined the influence of overweight and obesity on pulmonary function, exercise tolerance, quality of life and response to pulmonary rehabilitation in COPD. METHODS 261 patients with COPD were divided into three groups: normal body mass index (BMI), overweight and obese. Baseline and post rehabilitation pulmonary function, 6-min walking(More)
Pressurized whey supplementation, by its antioxidant and nutritional properties, may improve exercise tolerance and potentiate the effects of exercise training in patients with chronic obstructive pulmonary disease (COPD). In this randomized, double-blind, placebo-controlled study, 22 patients with COPD were allocated to receive active pressurized whey or(More)
Patients with pulmonary arterial hypertension (PAH) may exhibit reduced expiratory flows at low lung volumes, which could promote exercise-induced dynamic hyperinflation (DH). This study aimed to examine the impact of a potential exercise-related DH on the intensity of dyspnoea in patients with PAH undergoing symptom-limited incremental cardiopulmonary(More)
Exercise intolerance in chronic obstructive pulmonary disease (COPD) results from a complex interaction between central (ventilatory) and peripheral (limb muscles) components of exercise limitation. The purpose of this study was to evaluate the influence of quadriceps muscle fatigue on exercise tolerance and ventilatory response during constant-workrate(More)
RATIONALE The endurance time (T(end)) during constant-workrate cycling exercise (CET) is highly variable in COPD. We investigated pulmonary and physiological variables that may contribute to these variations in T(end). METHODS Ninety-two patients with COPD completed a CET performed at 80% of peak workrate capacity (W(peak)). Patients were divided into(More)
INTRODUCTION In humans, cortical mechanisms can interfere with autonomic breathing. Respiratory-related activation of the supplementary motor area (SMA) has been documented during voluntary breathing and in response to inspiratory constraints. The SMA could therefore participate in the increased resting state of the respiratory motor system during wake(More)
BACKGROUND Chronic obstructive pulmonary disease (COPD) and a high body mass index (BMI) can both affect pulmonary volumes as well as exercise tolerance, but their combined effect on these outcomes is not well known. The aim of this study was to investigate the effects of increased BMI during constant workrate cycle ergometry in patients with COPD. (More)
Patients with chronic obstructive pulmonary disease (COPD) are often caught in a downward spiral that progresses from expiratory flow limitation to poor quality of life and invalidity. Within this downward spiral, exercise tolerance represents a key intermediate outcome. As recently stated by the GOLD initiative, improvement in exercise tolerance is now rec(More)