Introduction: Research trials that involve testing of physiological response to exercise and that include tests
from more than one institution, or tests across long time periods, may be required to include tests from different ergometer
types, mainly treadmill or leg cycle ergometer. The purpose of this study was to establish equivalence of metabolic demand
when comparing treadmill to cycle ergometer protocols.
Methods: Published equations were used to derive external power output performed on a cycle ergometer and treadmill to
match external power output performance across the range of typical body weights for subjects.
Results: When comparing a submaximal walking versus 10-watt incremental cycling protocol, the percent difference in
metabolic demand ranged from -35% to 39% across the range of body weights from 50 kg to 150 kg. For the modified
Bruce treadmill protocol, watts on the cycle had to be increased to match metabolic demand as body weight of the subject
Conclusion: To match estimated external power output performed on a treadmill, external power output on a leg cycle ergometer
must be increased as body weight increases.