BACKGROUND The cardiac output-O2 uptake (VO2) relation, which is thought to be linear and predictable in normal humans, has not been clarified in cardiac patients. We evaluated the relation between cardiac output and VO2 during the incremental exercise test in patients with previous myocardial infarction. METHODS AND RESULTS Twenty-two patients (age, 58.1 +/- 8.0 years) with previous myocardi...

The mechanism(s) underlying the attenuation of the slow component of pulmonary O2 uptake (Vo2) by prior heavy-intensity exercise is (are) poorly understood but may be ascribed to either an intramuscular-metabolic or a circulatory modification resulting from "priming" exercise. We investigated the effects of altering the circulatory dynamics by delayed vagal withdrawal to the circulation induced...

Prediction models of the oxygen uptake (VO2) from electromyograms (EMG) lower limb and respiratory muscles during an incremental exercise test were examined. Healthy male adults (n=15) underwent using a cycle ergometer. To predict patterns VO2, we used type recurrent neural network, long short-term memory. The measured VO2 as training data for deep learning, two prediction input values set: mus...

BACKGROUND Both Peak Oxygen Uptake (peak VO2), from cardiopulmonary exercise testing (CPET) and the distance walked during a Six-Minute Walk Test (6 MWD) are used for following the natural history of various diseases, timing of procedures such as transplantation and for assessing the response to therapeutic interventions. However, their relationship has not been clearly defined. METHODS We de...

The oxygen uptake (VO2) attained during a constant speed 800-m pace trial on a treadmill is less than the maximal VO2 (VO2max) in male middle-distance runners with a high VO2max (i.e., > 65 ml x kg (-1) x min (-1)). We therefore investigated whether the VO2 attained was influenced by the pacing strategy adopted. Eight male middle-distance runners (age 25.8 +/- 3.3 years; height 1.78 +/- 0.10 m;...

BACKGROUND The 6-minute walk test evaluates the effect of pharmacologic intervention in adults with pulmonary arterial hypertension (PAH) but, for reasons of compliance or reliability, may not be appropriate for children at all ages. Thus, peak oxygen consumption (VO2, maximal exercise test) was used instead in a pediatric PAH trial (STARTS-1) to evaluate pharmacologic intervention with sildena...

STUDY OBJECTIVE The mechanism of exercise intolerance in hyperthyroidism has not been fully elucidated. This study was undertaken to determine if hyperthyroidism reduced the efficiency of sub-maximal exercise. STUDY DESIGN We measured cardiorespiratory variables up to the anaerobic threshold (AT) during ramp-loading cycle ergometry in 12 patients (New York Heart Association functional class I...

Prior exercise has the potential to enhance subsequent performance by accelerating the oxygen uptake (VO2) kinetics. The present study investigated the effects of two different intensities of prior exercise on pulmonary VO2 kinetics and exercise time during subsequent exhaustive rowing exercise. It was hypothesized that in prior heavy, but not prior moderate exercise condition, overall VO2 kine...

The effect of propranolol on cardiac patients undergoing exercise training is reported to increase exercise tolerance and maximum oxygen uptake (VO2 max) but its effect on anaerobic threshold (AT) is unknown. It was the purpose of this study to determine the role of exercise training with propranolol on AT in patients with coronary artery disease (CAD). Eight men and one woman with significant ...