Criteria to verify attainment of maximal exercise tolerance test with obese females.

This study compared criteria used to determine attainment of maximal ETT used with normal subjects to results shown by obese subjects. Results indicated that obese subjects do not show the values that normal subjects show for plateau in oxygen consumption, respiratory exchange ratio, predicted maximal heart rate, or perceived exertion. Generally, less than 60% of the obese subjects met criteria for maximal ETT. These findings suggest that alternate criteria and/or alternate testing are needed to ascertain that ETT was maximal. Suggestions include longer treadmill stage times and the use of blood lactate.