New Data-based Cutoffs for Maximal Exercise Criteria across the Lifespan

Purpose: To determine age-dependent cutoff values for secondary exhaustion criteria for a general population free of exercise limiting chronic conditions; to describe the percentage of participants reaching commonly used exhaustion criteria during a cardiopulmonary exercise test (CPET); and to analyze their oxygen uptake at the respective criteria to quantify the impact of a given criterion on the respective oxygen uptake ((V)over dotO(2)) values. Methods: Data from the COmPLETE-Health Study were analyzed involving participants from 20 to 91 yr of age. All underwent a CPET to maximal voluntary exertion using a cycle ergometer. To determine new exhaustion criteria, based on maximal respiratory exchange ratio (RERmax) and age-predicted maximal HR (APMHR), one-sided lower tolerance intervals for the tests confirming (V)over dotO(2) plateau status were calculated using a confidence level of 95% and a coverage of 90%. Results: A total of 274 men and 252 women participated in the study. Participants were nearly equally distributed across age decades from 20 to >80 yr. A (V)over dotO(2) plateau was present in 32%. There were only minor differences in secondary exhaustion criteria between participants exhibiting a (V)over dotO(2) plateau and participants not showing a (V)over dotO(2) plateau. New exhaustion criteria according to the tolerance intervals for the age group of 20 to 39 yr were: RERmax >= 1.13, APMHR(210)- age >= 96%, and APMHR(208)x 0.7 age >= 93%; for the age group of 40 to 59 yr: RERmax >= 1.10, APMHR(210)- age >= 99%, and APMHR(208) x 0.7 age >= 92%; and, for the age group of 60 to 69 yr: RERmax >= 1.06, APMHR(210)- age >= 99%, and APMHR(208) x 0.7 age >= 89%. Conclusions: The proposed cutoff values for secondary criteria reduce the risk of underestimating (V)over dotO(2max). Lower values would increase false-positive results, assuming participants are exhausted although, in fact, they are not.