Novel CPET Reference Values in Healthy Adults: Associations with Physical Activity

Cardiopulmonary exercise testing (CPET) is an important measurement in clinical practice, and its primary outcome, maximal oxygen uptake (V˙O2peak), is inversely associated with morbidity and mortality. The purposes of this study are to provide CPET reference values for maximal and submaximal parameters across the adult age spectrum of a healthy European cohort, to compare V˙O2peak values with other reference data sets, and to analyze the associations between physical activity (PA) levels and CPET parameters.

In this cross-sectional study, we prospectively recruited 502 participants (47% female) from 20 to 90 yr old. The subjects performed a CPET on a cycle ergometer using a ramp protocol. PA was objectively and continuously measured over 14 d using a triaxial accelerometer. Quantile curves were calculated for CPET parameters. To investigate the associations between CPET parameters and PA levels, linear regression analysis was performed.

V˙O2peak values observed in the group of 20-29 yr were 46.6 ± 7.9 and 39.3 ± 6.5 mL·kg⋅min for males and females, respectively. On average, each age category (10-yr increments) showed a 10% lower V˙O2peak relative to the next younger age category. V˙O2peak values of previous studies were on average 7.5 mL·kg⋅min (20%) lower for males and 6.5 mL·kg⋅min (21%) lower for females. There was strong evidence supporting a positive association between the V˙O2peak (mL·kg⋅min) and the level of habitual PA performed at vigorous PA (estimate, 0.26; P < 0.001].

Maximal and submaximal CPET reference values over a large age range are novel, and differences to other studies are clinically highly relevant. Objectively measured vigorous-intensity PA showed a strong positive association with higher V˙O2peak and other performance-related CPET parameters, supporting the implementation of higher-intensity aerobic exercise in health promotion.