Correction to: Study protocol and rationale of the "Cogniaction project" a cross-sectional and randomized controlled trial about physical activity, brain health, cognition, and educational achievement in schoolchildren - Patricio Solis-Urra; Jorge Olivares-Arancibia; Ernesto Suarez-Cadenas; Javier Sanchez-Martinez; Fernando Rodríguez-Rodríguez; Francisco B. Ortega; Irene Esteban-Cornejo; Cristina Cadenas-Sanchez; Jose Castro-Piñero; Alejandro Veloz; Steren Chabert; Kabir P. Sadarangani; et al. (BMC, 2021)