RESUMEN
The EPInfant scale was developed to quantify perceived exertion (PE) during exercise in children and adolescents. OBJECTIVE: to determine the criterion validity of the EPInfant scale in children in the estimation and production paradigm considering oxygen consumption (VO2) as the reference standard. SUBJECTS AND METHOD: Twenty healthy boys, aged 9.8 ± 1.5 years, were selected. They all performed an incremental shuttle walking test (ISWT) followed by a perceptual regulated-exercise test (PRET). VO2 and heart rate (HR) were recorded during both exercise tests. Average VO2 and HR values were considered as a perceptual reproduction test (PRT). EPInfant's validity in estimating the exercise intensity was evaluated by regression analysis between VO2, HR, and PE during ISWT and PRET. RESULTS: All regression analysis models showed a robust positive relationship between PE and benchmarks (r2 > 0.90). The intraclass correlation coefficient for VO2 and HR was 0.89 (0.70 to 0.96) and 0.64 (0.08 to 0.86), respectively. Low mean discordance for VO2 and HR was observed in the Bland-Altman analysis. CONCLUSION: The EPInfant scale presented adequate criterion validity for estimating and regulating running exercise intensity in boys between 8 and 12 years.