This study tested the effects of inhaled nitric oxide [NO; 20 parts per million (ppm)] during normoxic and hypoxic (fraction of inspired O(2) = 14%) exercise on gas exchange in athletes with exercise-induced hypoxemia. Trained male cyclists (n = 7) performed two cycle tests to exhaustion to determine maximal O(2) consumption (VO(2 max)) and arterial oxyhemoglobin saturation (Sa(O(2)), Ohmeda Bi...

The purpose of this study was to assess whether maximal oxygen uptake (V.O(2 max)) could be predicted from submaximal ratings of perceived exertion (RPE) elicited during the multistage fitness test (MFT). Eleven female volunteers completed three maximal exercise tests in random order; the MFT, a simulated MFT on a motorized treadmill and a graded exercise test to volitional exhaustion (GXT), al...

We investigated the effects of myocardial temperature on left ventricular (LV) mechanoenergetics in the excised, cross-circulated canine heart. We used the framework of the LV contractility ( E max)-pressure-volume area (PVA; a measure of total mechanical energy)-myocardial oxygen consumption (Vo 2) relationship. We have shown this framework to be useful to integrative analysis of the mechanoen...

An increase in the responsiveness of the contractile machinery to Ca2+could theoretically enhance the mechanoenergetics of the heart. To clarify this unresolved issue, we studied the effects of MCI-154, a Ca2+ sensitizer, on the mechanoenergetics in terms of the left ventricular contractility index [slope of end-systolic pressure-volume relationship ( E max)] and the relationship between myocar...

The purpose of this study was to examine whether the heart rate (HR) deflection point (HRDP) in the HR-power relationship is concomitant with the maximal stroke volume (SV(max)) value achievement in endurance-trained subjects. Twenty-two international male cyclists (30.3 +/- 7.3 yr, 179.7 +/- 7.2 cm, 71.3 +/- 5.5 kg) undertook a graded cycling exercise (50 W every 3 min) in the upright position...

BACKGROUND The role of the perception of breathing effort in the regulation of performance of maximal exercise remains unclear. AIMS To determine whether the perceived effort of ventilation is altered through substituting a less dense gas for normal ambient air and whether this substitution affects performance of maximal incremental exercise in trained athletes. METHODS Eight highly trained...

BACKGROUND In congestive heart failure (CHF), the prognostic significance of impaired respiratory muscle strength has not been established. METHODS AND RESULTS Maximal inspiratory pressure (Pi(max)) was prospectively determined in 244 consecutive patients (207 men) with CHF (ischemic, n=75; idiopathic dilated cardiomyopathy, n=169; age, 54+/-11 years; left ventricular ejection fraction [LVEF]...