Exponential protocols for cardiopulmonary exercise testing on treadmill and cycle ergometer.

An extended exponential exercise protocol was validated by comparing submaximal and maximal parameters with those obtained by linear protocol. Normal subjects (n = 16, 20-69 years) undertook maximal exercise tests on treadmill and cycle ergometer. The subjects had a wide range of exercise capacity, and all were accommodated by the protocol. Mean oxygen uptake (V(O2)) agreed between protocols at gas exchange anaerobic threshold (theta) (95% CI of difference -0.1 to +0.06 l min(-1)) and at peak (95% CI of difference -0.1 to +0.1 l min(-1)). Mean pre-thetaDeltaV(O2)/Deltawork rate (W) slope on the cycle ergometer agreed between protocols (95% CI of the difference -0.9 to +0.25 ml min(-1) W(-1)). Post-thetaDeltaV(O2)/DeltaW slope was steeper than pre-theta, and steeper by linear than by exponential protocol (P = 0.0001). It is concluded that the exponential protocol is valid for the measurement of submaximal and maximal exercise parameters in subjects with a wide range of exercise capacity.