To determine if socioeconomic status (SES) has a greater effect than standard demographic values on predicted peak oxygen consumption (pVO₂).

We conducted a single-institution, retrospective analysis of maximal cardiopulmonary exercise test (CPET) data from 2010 to 2020 for healthy patients age <19 years with body mass index (BMI) percentile (BMI%) between 5-95. Data were sorted by self-identified race, BMI%, and adjusted gross income (AGI); AGI served as a surrogate for SES. Mean percent predicted pVO₂ (pppVO₂) was compared between groups. Linear regression was used to adjust for differences.

A total of 541 CPETs met inclusion criteria. Mean pppVO₂ was 97% ± 22.6 predicted (P < .01) with 30% below criterion standard for normal (85% predicted). After excluding unknown AGI and race, 418 CPETs remained. Mean pppVO₂ was lower for Blacks (n = 36) and Latinx (n = 26) compared with Whites (n = 333, P < .01). Mean pppVO₂ declined as AGI decreased (P < .01). The differences in pppVO₂ between racial categories remained significant when adjusted for BMI% (Black r = −7.3, P = .035; Latinx r = −15.4, P < .01). These differences both decreased in magnitude and were no longer significant when adjusted for AGI (Black r = −6.0, P = .150; Latinx r = −9.3, P = .06).

Lower SES correlates with lower measured cardiovascular fitness and may confound data interpretation. When using normative reference ranges in clinical decision making, providers should recognize that social determinants of health may influence predicted fitness. Social inequities should be considered when assessing pediatric cardiovascular fitness.