Prediction of Maximal Oxygen Consumption During Handrail-Supported Treadmill Exercise

Equations derived during non-handrail-supported treadmill exercise may be inappropriate for predicting maximum oxgyen consumption (VO2max) during tests that allow the use of front handrail support. Maximum oxygen consumption was measured during exercise tests performed on 78 patients with coronary heart disease (CHD) and S3 healthy persons. Each test used the Bruce protocol and allowed the use of handrail support. Step-down multiple-regression analysis found that treadmill time (TT) and age were significant predictors of VO2max. A cross-validation group (N = 17) was then tested to compare the accuracy of the equations accounting for the use of handrail support with other previously derived equations. The mean prediction error was signficantly less (P < .01) in the present equations when compared with that calculated by Bruce and colleagues' formula and by Foster and associates'. There were no differences in the prediction error between equations allowing for or not allowing for age regarding VO2max values. Bruce's and Foster's equations significantly (P < .01) overpredicted VO2max. It may therefore be concluded that (1) when handrail support is allowed during treadmill exercise, VO2max must be estimated by equations derived from data obtained during exercise that accounts for handrail support, and (2) a simple linear regression analysis using TT alone provides an accurate estimate of VO2max during treadmill tests that allow handrail support for patients with CHD and for healthy individuals.