What is the clinical evidence from this study?

Study design: Cross-Sectional. Population: Apparently healthy adults (n=3534). Intervention: Obesity (BMI ≥ 30 kg/m2) vs. Without obesity (BMI < 30 kg/m2). Primary outcome: V̇E/V̇CO2 slope (ρ 0.079, p=<0.001).

What question did this study set out to answer?

The research aims to determine the association between BMI and V̇E/V̇CO2 slope in apparently healthy adults using data from the FRIEND database.

March 21, 2026Open Access

Obesity and Ventilatory Responses During Exercise in the Fitness Registry and the Importance of Exercise National Database ( FRIEND )

Q: What are the key findings of this study?

Obesity was positively but negligibly associated with a higher V̇E/V̇CO2 slope during exercise compared to adults without obesity (median 25.0 vs 24.7; p<0.001).

Q: What question did this study set out to answer?

The research aims to determine the association between BMI and V̇E/V̇CO2 slope in apparently healthy adults using data from the FRIEND database.

Key Result

Obesity was positively but negligibly associated with a higher V̇E/V̇CO2 slope during exercise compared to adults without obesity (median 25.0 vs 24.7; p<0.001).

Key Points

The research aims to determine the association between BMI and V̇E/V̇CO2 slope in apparently healthy adults using data from the FRIEND database.
Participants completed a cardiopulmonary exercise test on a cycle ergometer.
Linear regressions were utilized to compare V̇E/V̇CO2 slope between adults with and without obesity.
Partial correlation analysis was performed to examine the relationship between V̇E/V̇CO2 slope and BMI.
V̇E/V̇CO2 slope was higher in adults with obesity (25.0) compared to those without (24.7).
The effect size was negligible (R² = 0.132).
A weak association was found between V̇E/V̇CO2 slope and BMI (ρ = 0.079).

Study Design

Type

Cross-Sectional (n=3,534)

Multicenter

Yes

Structured PICO

Is obesity associated with a higher V̇E/V̇CO2 slope during exercise in apparently healthy adults?

Population

3,534 apparently healthy adults from the Fitness Registry and the Importance of Exercise National Database (FRIEND), median age 40, 20% female.

Intervention

Obesity (BMI ≥ 30 kg/m2)

Comparator

Without obesity (BMI < 30 kg/m2)

Outcome

Minute ventilation/rate of carbon dioxide production (V̇E/V̇CO2) slope during cardiopulmonary exercise test on a cycle ergometersurrogate

Obesity is positively but negligibly associated with a higher V̇E/V̇CO2 slope during exercise in apparently healthy adults.

Main Result

Effect estimate: ρ 0.079

Absolute Event Rate: 25% vs 24.7%

p-value: p=<0.001

Abstract

ABSTRACT A high minute ventilation/rate of carbon dioxide production (V̇ E /V̇CO 2 ) slope during exercise is prognostic for cardiovascular mortality among clinical populations. Obesity represents a major modifiable risk factor for cardiovascular disease. However, it is unclear whether body mass index (BMI) is associated with V̇ E /V̇CO 2 slope among apparently healthy adults. Therefore, we used the Fitness Registry and the Importance of Exercise National Database (FRIEND) to determine whether BMI is positively associated with V̇ E /V̇CO 2 slope in the context of apparently healthy adults. All participants completed a cardiopulmonary exercise test on a cycle ergometer. Linear regressions adjusted for age, sex, and race/ethnicity were used to compare the V̇ E /V̇CO 2 slope between adults with and without obesity (BMI </≥ 30 kg/m 2 ). Partial correlation adjusted for age, sex, race/ethnicity, and cardiorespiratory fitness was used to determine the relation between the V̇ E /V̇CO 2 slope and BMI. All data are presented as median IQR. We set α a priori to < 0.05. The sample ( n = 3534) characteristics were as follows: (1) age = 40 (17) years; (2) 20% female; (3) cardiorespiratory fitness = 27.810.8 mL O 2 ●kg −1 ●min −1 and (4) BMI = 26.15.0 kg/m 2 . V̇ E /V̇CO 2 slope was higher in adults with obesity 25.03.5 compared to those without obesity 24.73.6 with a negligible effect size ( R 2 = 0.132, adjusted R 2 = 0.131, F 4,3529 = 134, p < 0.001). V̇ E /V̇CO 2 slope was weakly associated with BMI across the cohort (ρ = 0.079, p < 0.001). Obesity was positively, but negligibly, associated with a higher V̇ E /V̇CO 2 slope in the FRIEND Registry.