At present, there is no evidence regarding the effects of an interdisciplinary program, based on physical training, on respiratory muscle strength (FMR) in obese schoolchildren. The objective was to analyze the effects of a three-month interdisciplinary intervention program on fat mass (MA), muscle mass (MM) and FMR in schoolchildren with childhood obesity and without respiratory pathology. 11 schoolchildren, seven males and four female, participated during three months of the interdisciplinary program. Supervised by nutritionists, psychologists and trainers. FMR was evaluated with pimometry and body composition (CC) with anthropometry. There was a significant increase in FMR, expressed as maximum inspiratory pressure (PIM) (p = 0.029) and maximum expiratory pressure (PEM) (p = 0.006) in relation to their reference and absolute values. A significant decrease in the BMI score was found (p = 0.04), as well as associations between PIM (PIM / MA p = 0.005; r =-0.769) and PEM (PEM / MM p = 0.001; r = 0.835) with variables of CC. In conclusion, three months of interdisciplinary treatment of childhood obesity evoke increases in PIM and PEM, and these increases are associated with variations in CC.