Abstract
The objective of this study was to examine the effects of obesity on the oxygen (O(2)) cost of breathing using the eucapnic voluntary hyperpnea (EVH) technique in 10- and 11-year-old children. Seventeen children (8 without and 9 with obesity) underwent EVH trials at two levels of ventilation for assessing the O(2) cost of breathing (slope of oxygen uptake, V˙O(2) vs. minute ventilation) and a dual energy x-ray absorptiometry scan. Resting and EVH V˙O(2) was higher in children with obesity when compared with children without obesity (P = 0.0096). The O(2) cost of breathing did not statistically differ between children without (2.09 ± 0.46 mL/L) and with obesity (2.08 ± 0.64 mL/L, P = 0.99), but the intercept was significantly greater in children with obesity. Chest mass explained 85 % of the variance in resting V˙O(2) in children with obesity. Higher resting energy requirements, attributable to increased chest mass, can increase the absolute metabolic costs of exercise and hyperpnea in children with obesity.