The thermal dependencies of endurance and the rates of oxygen cnsumption (VO2) and carbon dioxide production (VCO2) were determined for the lizard Dipsosaurus dorsalis walking on a treadmill. The thermal dependencies of endurance and maximal VO2 (VO2 max) are nerly identical. The maximal sustainable speed and the speed at which VO2 max is attained at each experimental body temperature are the s...

Previous investigators have reported that oxygen consumption (VO2) continues to rise after the initial 2- to 3-min transient period of exercise when work exceeds approximately 60% of VO2 max. The purpose of this investigation was to examine the possible causes of this slow rise in VO2. Eighteen subjects exercised for 20 min at 65% and at 80% of VO2 max on the bicycle ergometer. VO2, ventilation...

BACKGROUND AND PURPOSE Cardiovascular and pulmonary factors contributing to impaired peak oxygen uptake (VO2) in patients with stroke (SP) are not well known. We assessed cardiovascular function, pulmonary gas exchange, and ventilation in SP and healthy age, gender, and activity-matched control subjects. METHODS Ten hemiparetic SP and 10 control subjects were enrolled. Subjects completed cycl...

Critical power (CP) is lower at faster rather than slower pedalling frequencies and traditionally reported in watts (W). Faster pedalling frequencies also engender a greater metabolic rate (VO2) at low work rates, but with progressive increases in power output, the initial difference in VO2 between fast and slower pedalling frequencies is reduced. We tested the hypothesis that CP represents a u...

BACKGROUND For many patients clinical prescription of walking will be beneficial to health and accelerometers can be used to monitor their walking intensity, frequency and duration over many days. Walking intensity should include establishment of individual specific accelerometer count, walking speed and energy expenditure (VO2) relationships and this can be achieved using a walking protocol on...

OBJECTIVES This study was undertaken to determine which exercise and radionuclide ventriculographic variables predict prognosis in advanced heart failure. BACKGROUND Although cardiopulmonary exercise testing is frequently used to predict prognosis in patients with advanced heart failure, little is known about the prognostic significance of ventriculographic variables. METHODS The results of...

BACKGROUND Reduced muscle aerobic capacity in COPD patients has been demonstrated in several laboratories by phosphorus magnetic resonance spectroscopy and by analysis of oxygen uptake (VO2) kinetics. COPD patients are usually elderly, hypoxemic, poorly active with muscle atrophy, and often malnourished. Under these conditions there is usually reduction of O2 delivery to the tissues (bulk O2 fl...

We studied relations between maximal O2 consumption (VO2 max) during forced exercise and subordinate traits associated with blood O2 transport and cellular respiration in four lines of mice selectively bred for high voluntary wheel running (S lines) and their four nonselected control (C) lines. Previously, we reported VO2 max of 59 females at three Po2 (hypoxia = 14% O2, normoxia = 21%, hyperox...

INTRODUCTION Lactic acidosis can develop during biguanide (metformin and phenformin) intoxication, possibly as a consequence of mitochondrial dysfunction. To verify this hypothesis, we investigated whether body oxygen consumption (VO2), that primarily depends on mitochondrial respiration, is depressed in patients with biguanide intoxication. METHODS Multicentre retrospective analysis of data ...