Sleep deprivation is common among university students, and has been associated with poor academic performance and physical dysfunction. However, current literature has a narrow focus in regard to domains tested, this study aimed to investigate the effects of a night of sleep deprivation on cognitive and physical performance in students. A randomized controlled crossover study was carried out wi...

BACKGROUND Cardiopulmonary exercise testing (CPET) has become an important modality for the evaluation and management of patients with a diverse array of medical problems. However, interpreting these tests is often difficult and time consuming, requiring significant expertise. METHODS We created a computer software program (XINT) that assists in CPET interpretation. The program uses an integr...

INTRODUCTION Exercise oxygen pulse (O₂ pulse), a surrogate for stroke volume and arteriovenous oxygen difference, has emerged as an important variable obtained during cardiopulmonary exercise testing. OBJECTIVES We hypothesized that the O₂ pulse curve pattern response to a maximal cycling ramp protocol exhibits a stable linear pattern in subjects reevaluated under the same clinical conditions...

Background Reduced exercise capacity is a common feature of many cardiovascular diseases. Quantitative assessment of exercise capacity is usually achieved by measuring peak oxygen consumption (VO2). However, measuring peak VO2 alone neglects the different components of reduced exercise capacity: namely reduced cardiac output (CO) and oxygen extraction (ΔcO2). A better approach would be to simul...

Two new definitions of exercise-induced pulmonary hypertension (EIPH) have emerged. Both rely on measuring cardiac output (CO), yet this remains unstandardized. In our cohort of patients undergoing invasive cardiopulmonary exercise testing, we found that using thermodilution CO rather than direct Fick CO led to a significant excess of EIPH diagnoses.

BACKGROUND Peak oxygen uptake (VO2peak) via cardiopulmonary exercise testing is considered the gold standard for testing aerobic capacity in healthy participants and people with various medical conditions. The reliability and responsiveness of cardiopulmonary exercise testing outcomes in persons with MS (PwMS) have not been extensively studied. OBJECTIVE (1) to investigate the reliability of ...

Cardiopulmonary exercise testing (CPX) is a relatively old technology, but has sustained relevance for many primary care clinical scenarios in which it is, ironically, rarely considered. Advancing computer technology has made CPX easier to administer and interpret at a time when our aging population is more prone to comorbidities and higher prevalence of nonspecific symptoms of exercise intoler...

BACKGROUND Transient increases (overshoot) in respiratory gas variables have been observed during exercise recovery, but their clinical significance is not clearly understood. Our group evaluated the relationship between the presence of overshoot of respiratory gas variables and the parameters obtained from cardiopulmonary exercise testing (CPX). METHODS AND RESULTS In total, 227 patients wit...

BACKGROUND The reference values for cardiopulmonary exercise testing (CPET) available in Brazil were derived from a cycle ergometer in a sedentary and relatively small population. OBJECTIVE Provide reference values for CPET in Brazilians of both sexes, either sedentary or active. METHODS From 2006 to 2008, 3,992 CEPT of healthy individuals were selected from our laboratory. Athletes, smoker...

OBJECTIVE: To assess the influence of central obesity on the magnitude of the error of estimate of maximal oxygen uptake in maximal cycling exercise testing. METHOD: A total of 1,715 adults (68% men) between 18-91 years of age underwent cardiopulmonary exercise testing using a progressive protocol to volitional fatigue. Subjects were stratified by central obesity into three quartile ranges: Q...