Impact of Increasing Levels of Obesity on Functional Capacity and Cardiorespiratory Fitness in Children

Purpose: This study aims to evaluate the impact of increasing severity of childhood obesity on cardiorespiratory fitness (CRF) using cardiopulmonary exercise testing. Methods: A retrospective analysis of cardiopulmonary exercise testing data from patients <21 years of age was performed. Patients were categorized by body mass index percentile into 4 classes. CRF was assessed and compared between groups by relative peak VO2 and metabolic equivalents achieved at limit of tolerance. Results: A total of 204 patients were included in the study. Significantly lower relative peak VO2 and metabolic equivalents and higher adjusted peak VO(2 )were achieved with increasing obesity. Resting and recovery heart rates (HRs) were significantly higher in Class III compared with the nonobese patients (P = .001 and .003, respectively). Class III patients had a significantly greater HR at anaerobic threshold relative to maximum HR achieved compared with the nonobese patients (P = .002). There was no significant difference between groups in the rating of perceived exertion at peak exercise, peak O-2 pulse, or maximum HR achieved. Conclusion(s): Our study has shown that CRF worsens with increasing levels of obesity. Cardiopulmonary exercise testing can be used as an objective measure to assess CRF as a target for intervention in childhood obesity for pediatricians. Improvement in fitness is an achievable outcome, which also translates into improved cardiometabolic health.