RESUMEN
This study aimed to analyze the use of public open spaces and physical activity levels among children and adolescents in the city of Rivera, Uruguay. A total of 88 target areas located in 29 public open spaces were observed using the System for Observing Play and Recreation in Communities (SOPARC). Systematic observations were made at different times of the day, covering both weekdays and weekends, for a total of 792 records in each public open spaces. Characteristics of the users were recorded according to gender (male and female), age group (infancy to early childhood 0-5 years, middle childhood 6-12 years, adolescence 13-18 years) and physical activity level (sedentary, moderate, or vigorous activity). Logistic regression was employed, considering variables such as day, period, type, and conditions, to assess factors associated with user presence and activity, with separate analyses by gender. Most of the users were adolescents (59.8%) between 13 and 18 years, 67.2% were male and half of the users were sedentary (50.1%). Furthermore, the majority of participants used the target areas on weekends (96.2%), particularly in the evening (99.2%). Multivariate analyses revealed elevated odds of having active girls and boys in the target area during the afternoon and evening, particularly in organized and equipped areas, compared to the morning. Based on this information, it is worth proposing the need to promote the active use of public open spaces in the city of Rivera (Uruguay).