https://www.selleckchem.com/products/dyngo-4a.html Introduction in children the use of therapeutic interventions, which includes the administration of medications, is based on body weight. Objective to validate the equations proposed by "Advanced Pediatric Life Support - APLS" in 2011 (APLS 1) and 2001 (APLS 2) to estimate weight in Ecuadorian girls and boys, considering their ethnic diversity and age groups. Methods a cross-sectional study which included 21,735 girls and boys belonging to three ethnic groups mestizo, indigenous, and other (white, black, and mulatto), with ages between 0 and 12 years, who participated in the ENSANUT-ECU study. Differences, Spearman's correlation, Bland-Altman graphs, and percentage error (PE) were calculated. Data were processed and analyzed using R. Results APLS 1 tends to overestimate weight whereas APLS 2 underestimates it. The estimated weight bias was greater for the classical equation. The indigenous and "other" ethnic groups presented the highest differences with respect to measured weight. The differences between estimated weight and measured weight increased progressively with age. With APLS 1, the percentage of individuals with a PE > 10 % was greater than with APLS 2. Conclusions APLS does not accurately estimate weight in the Ecuadorian pediatric population. The difference between estimated weight and measured weight is sensitive to ethnic and age differences. 10 % was greater than with APLS 2. Conclusions APLS does not accurately estimate weight in the Ecuadorian pediatric population. The difference between estimated weight and measured weight is sensitive to ethnic and age differences. Introduction there has been an increase in the number of endurance sports events during the last 20 years, as well as in the number of their participants. An adequate nutritional plan is essential for a satisfactory performance in this type of events, both in professional and amateur athletes. Objectives the objective was to determine, e