BACKGROUND The relative contributions of decreases in maximal heart rate, stroke volume, and oxygen extraction and of changes in body weight and composition to the age-related decline in maximal oxygen uptake (VO2max) are unclear and may be influenced by sex and level of physical activity. METHODS AND RESULTS To investigate mechanisms by which aging, sex, and physical activity influence VO2ma...

BACKGROUND The pupillary light reflex is a critical component of the neurologic examination, yet whether it is present, depressed, or absent is unknown in patients with significant opioid toxicity. Although opioids produce miosis by activating the pupillary sphincter muscle, these agents may induce significant hypercarbia and hypoxia, causing pupillary constriction to be overcome via sympatheti...

the aim of this study was to investigate the effect of endurance, resistance and concurrent training on plasma leptin levels of male students. for this purpose, 48 male university students (mean age 21.45 years) participated in this study. subjects were randomly assigned to three exercise groups: endurance group (n=12), resistance group (n=12) and concurrent group (n=12) and a control group (n=...

To delineate the effects of true aging, undetected heart disease and deconditioning on heart rate, we performed 24-hour ambulatory electrocardiography and maximal exercise stress test on 101 subjects with normal hearts. The maximal heart rate recorded was 180 beats/min; the minimum was 35 beats/min. A distinct diurnal pattern was observed. With increasing age, a decrease of the maximal heart ra...

PURPOSE To compare peak exercise oxygen consumption (VO2peak) of healthy individuals with asymptomatic individuals with probable heart disease. METHODS Ninety-eight men were evaluated. They were divided into two groups: 1) 39 healthy individuals (group N) with an age range of 50 +/- 4.6 years; and 2) 59 asymptomatic individuals with signs of atherosclerotic and/or hypertensive heart disease (...