The Response of Healthy Men to Treadmill Exercise ROGER

THE INTERPRETATION OF ELECTROCARDIOGRAPHIC CHANGES in response to exercise testing is of established value in the early detection, diagnosis, and subsequent management of coronary atherosclerotic heart disease (CAD).'` The major emphasis placed on interpretation of the exercise electrocardiogram (ECG) has, however, tended to de-emphasize the value and significance of other commonly acquired exercise performance measurements (i.e., heart rate, blood pressure, and functional capacity). These latter measurements are currently attracting renewed attention as part of an effort to improve the overall sensitivity and specificity of exercise testing. Recent reports have suggested that maximal oxygen consumption,6 functional aerobic capacity estimated from maximal treadmill time,7 8 maximal and submaximal heart rate and blood pressure,9-" and the maximal heart rate-blood pressure product,'2 may also be useful indices for identifying the presence and/or severity of CAD in patients. The value of any measurement in providing useful diagnostic information from treadmill testing depends upon: a) the accuracy and completeness with which the measurement has been made in healthy individuals (the reference values); and b) the effectiveness with which certain limits of the measurement (discriminant values) separate healthy individuals from those with known health disorders.'3 Previously published studies have reported reference values based on the response of healthy individuals to treadmill testing. Unfortunately, a majority of these studies were based on a small sample size, and statistics based on them are less likely to provide a true estimate of population parameters than is a comparable study based on a larger number. In the remaining few studies with a larger sample size, data for both submaximal and postexertional treadmill responses are fragmentary and incomplete. Hence, the practicing clinician has not had a complete and readily available set of reference values for use with his application of treadmill exercise testing. The purpose of the present report is to establish a complete set of reference values for the response of healthy men