Ramos Munell, JavierAntczak, DevanÁlvarez Barbosa, FranciscoAlfonso Rosa, Rosa M.Pozo Cruz, Borja delPozo Cruz, Jesús del2026-01-142026-01-142025Ramos-Munell, J., Antczak, D., Álvarez-Barbosa, F., Alfonso-Rosa, R. M., Del Pozo Cruz, B., & Del Pozo-Cruz, J. (2025). Accelerometer monitoring duration for reliable estimates of physical activity, sedentary behavior, and step counts in preschoolers. Journal of Physical Activity and Health, 22(10), 1307-1314. https://doi.org/10.1123/jpah.2024-06401543-30801543-5474https://hdl.handle.net/11268/16712This study aims to establish the reliability of accelerometer-based measurements for physical activity, sedentary behavior, and step counts in preschoolers and determine the optimal monitoring duration necessary for reliable data. The study analyzed data from 434 preschoolers (ages 3–5) who wore waist-worn ActiGraph wGT3X-BT accelerometers for 7 days as part of the Sunrise Study in Spain. Two-way mixed effects intraclass correlation coefficients were calculated for various combinations of daily wear time and number of valid days to assess reliability. The Spearman–Brown prophecy formula was applied to determine the required days to achieve reliability scores of 0.7, 0.8, and 0.9.engReproducibilidad de los resultadosEjercicio físicoConducta sedentariajournal article10.1123/jpah.2024-0640embargoed accessNiño en edad preescolarInvestigación médicaMedicina preventivaGoal 3: Ensure healthy lives and promote well-being for all at all ages