Is BMI Associated with Cardiorespiratory Fitness? A Cross‑Sectional Analysis Among 8470 Apparently Healthy Subjects Aged 18–94 Years from the Low‑Lands Fitness Registry

T. Takken · H. J. Hulzebos

Journal of Science in Sport and Exercise

ObjectiveThe purpose of the present study was to investigate the association between cardiorespiratory fitness (CRF) measured as peak oxygen uptake (VO2peak, expressed in mL/min) and body mass index (BMI) in a large cohort of apparently healthy subjects.
MethodsBMI and VO2peak were measured in a cross-sectional study of 8470 apparently healthy adults. VO2peak (mL/min) was determined by an incremental cycle ergometer test to exhaustion. Linear regression analyses were performed to identify predictors of CRF.
ResultsThere was no difference in CRF between adults with a normal weight (BMI between 18.5–24.9 kg/m2) and those who were overweight (BMI 25.0–29.9 kg/m2). Subjects who were underweight (BMI < 18.5 kg/m2) as well as females who were obese (BMI ≥ 30.0 kg/m2) showed a reduced CRF compared to the normal and overweight groups. Age, height, and gender were significant predictors of CRF (R2 = 0.467, P < 0.0001); BMI did not add significantly to this relationship.
ConclusionOur findings indicate that BMI was not associated with CRF in addition to age, height, and gender. In subjects with a BMI < 18.5 kg/m2, CRF was lower compared to subjects with a BMI between 18.5 and 29.9 kg/m2. In obese subjects, CRF was only lower in females compared to females with a BMI between 18.5 and 29.9 kg/m2. Correcting CRF for BMI may be beneficial for subjects with a low BMI, and females with a BMI ≥ 30.0 kg/m2. The outcome of this study might help to improve the interpretation of exercise testing results in individuals with a low or high BMI.