The maximal exercise capacity of patients with chronic heart failure is frequently reduced. To investigate whether this exercise intolerance is caused by inadequate nutritive flow to skeletal muscle, we compared cardiac outputs, leg blood flow, and leg metabolism during maximal bicycle exercise in seven patients with normal maximal oxygen uptake (VO2) (greater than 20 ml/min/kg; group A), eight...

The effects of chronic dynamic exercise on myocardial /3-adrenergic and muscarinlc cholinergic receptors and chronotropic sensitivity to isoproterenol were studied in 5 Yucatan miniswine. Right atrial and left ventricular biopsies, heart rate responses to isoproterenol, and maximal exercise treadmill testing were obtained before and after 10-19 weeks of treadmill running. Radioligand studies us...

Twelve male patients, with effort angina and a history of cold intolerance, performed brief submaximal exercise bicycle tests with separation of inspiratory and room air. In one test, the patients exercised in a normal room (20°C), breathing either normal or very cold air (-35°C). In another test, environmental air \vas either normal or -10°C, and four combinations of inspiratory and room air w...

The effects of chronic dynamic exercise on myocardial beta-adrenergic and muscarinic cholinergic receptors and chronotropic sensitivity to isoproterenol were studied in 5 Yucatan miniswine. Right atrial and left ventricular biopsies, heart rate responses to isoproterenol, and maximal exercise treadmill testing were obtained before and after 10-19 weeks of treadmill running. Radioligand studies ...

Background: The primary purpose of this investigation was to determine the differences in resting heart rate variability and heart rate recovery between norm-referenced aerobic fitness groupings, independent of body composition, in Black men. Additionally, we sought to clarify the independent relationships that heart rate variability and heart rate recovery displayed with maximal aerobic fitnes...

An enduring hypothesis in exercise physiology holds that a limiting cardiorespiratory function determines maximal exercise performance as a result of specific metabolic changes in the exercising skeletal muscle, so-called peripheral fatigue. The origins of this classical hypothesis can be traced to work undertaken by Nobel Laureate A. V. Hill and his colleagues in London between 1923 and 1925. ...

BACKGROUND In professional soccer, a significant amount of training time is used to improve players' aerobic capacity. However, it is not known whether soccer specific training fulfils the criterion of effective endurance training to improve maximal oxygen uptake, namely an exercise intensity of 90-95% of maximal heart rate in periods of three to eight minutes. OBJECTIVE To determine whether ...