Abstract

This study aimed to evaluate the reliability, reproducibility, and feasibility of the Youth Activity Profile Questionnaire (YAP-SL) in the Chilean version (YAP-C) in a sample of children and adolescents. This cross-sectional study included 160 youth, 59 children (5-11 years old), and 101 adolescents (12-17 years old) from the city of Vi & ntilde;a del Mar (Chile). The YAP-SL is a 15-item self-report instrument which was administered twice at an interval of 7 days apart. This questionnaire was designed to capture physical activity (PA) and sedentary behaviour in youths in the last week, categorizing them into three domains: PA at school, PA out-of-school, and sedentary habits. Cronbach's alpha coefficients were calculated to evaluate the internal consistency (reliability), and the reproducibility was determined by test-retest and Kendall's tau b coefficients. Concerning the total YAP-C score, results indicated moderate-to-high reliability in the total sample (0.71), boys (0.76) and girls (0.66), as well as for children (0.73) and adolescents (0.70). The results also revealed variations in reliability and reproducibility across the three domains. In conclusion, the YAP-SL questionnaire presents moderate-to-high reliability in Chilean children and adolescents. However, the reliability and consistency of the YAP varied across the domains.