This duration has been justified on the basis of better reliability for studying the effects of therapy, higher values for maximal oxygen uptake, and an improvement in the relationship between oxygen uptake and work rate compared with shorter protocols employing large work increments. Because a major feature of the ramp test is an individualized change in work rate, a desired test duration can be roughly achieved.
Although we have recently compared the ramp test with standard treadmill and cycle ergometer protocols in a small group of patients with heart disease, to our knowledge, the present report is the first thorough evaluation of the protocol in a large sample. As part of a larger trial of normotensive and hypertensive subjects, this sample provided a convenient opportunity to evaluate the ramp treadmill test. Although 24% of these subjects had hypertension and thus high blood pressures were present at rest and during exercise, they were otherwise healthy, and oxygen kinetics should not have been affected. The mean treadmill time of 9.5 ±1.8 min indicates that the targeted duration was generally achieved, despite a wide spectrum of age and fitness levels.
Ramp testing using a cycle ergometer has been employed by several laboratories over the last decade for research purposes. Whipp and associates first described the ramp function test as a valid and reproducible means of assessing cardiopulmonary function. Davis et al extended these findings by demonstrating that the basic parameters of aerobic function studied by Whipp and coworkers (maximal oxygen uptake, the ventilatory threshold, the time constant for Vo2 kinetics, and work efficiency) were valid over a wide range of ramp rates (20 to 50 W/min) on a cycle ergometer.