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

Abstract

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˙O₂) 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 (RER_max) and age-predicted maximal HR (APMHR), one-sided lower tolerance intervals for the tests confirming V˙O₂ 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˙O₂ plateau was present in 32%. There were only minor differences in secondary exhaustion criteria between participants exhibiting a V˙O₂ plateau and participants not showing a V˙O₂ plateau. New exhaustion criteria according to the tolerance intervals for the age group of 20 to 39 yr were: RER_max ≥ 1.13, APMHR₂₁₀ − age ≥ 96%, and APMHR₂₀₈ × 0.7 age ≥ 93%; for the age group of 40 to 59 yr: RER_max ≥ 1.10, APMHR₂₁₀ − age ≥ 99%, and APMHR₂₀₈ × 0.7 age ≥ 92%; and, for the age group of 60 to 69 yr: RER_max ≥ 1.06, APMHR₂₁₀ − age ≥ 99%, and APMHR₂₀₈ × 0.7 age ≥ 89%.

Conclusions 

The proposed cutoff values for secondary criteria reduce the risk of underestimating V˙O_2max. Lower values would increase false-positive results, assuming participants are exhausted although, in fact, they are not.