text: The effects of the measures against COVID 19 pandemic on physical activity among school aged children and adolescents 6 17 years in 2020 A protocol for systematic review The pandemic of coronavirus disease COVID 19 has greatly changed peoples daily lives forcing countries to take actions such as school shutdown lockdown isolation and social distancing measures It remains unclear how the closures cancellations and restrictions of schools and courses as a response to the COVID 19 pandemic affect the engagement of school aged children and adolescents in relation to physical activity PA The articles in the databases of EBSCO including AMED CINAHL Plus Health Business Health Source MEDLINE with Full Text APA PsycArticles APA PsycINFO and SPORTDiscus published during the period from 1 January 2020 to 31 December 2020 will be retrieved and the data in the selected articles are extracted including research methods demographics and key results Search outcomes were reported according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses PRISMA guidelines The Mixed Methods Appraisal Tool MMAT will be used to evaluate research quality Two reviewers are responsible for completing the three tasks namely selecting the articles that meet the inclusion criteria extracting data in the articles selected and evaluating their research quality All findings and especially primary outcomes will be summarized in a table format of findings The results will provide a high quality synthesis of current evidence for researchers in this subject area The objective of this systematic review is to investigate the effects of the COVID 19 pandemic on PA in children and adolescents aged 6 17 years during 2020 1 What impact has the COVID 19 pandemic had on PA levels in school aged children and adolescents 2 Investigating changes in the locations of school aged childrens and adolescents PA between the pre COVID 19 period January 2020 and the COVID 19 period December 2020 We hope that this study will provide government authorities and health professionals with the necessary information in guiding actions and allocating resources so that the situation of physical inactivity in school aged children and adolescents during the COVID 19 pandemic can be improved thereby enhancing their physical health This review was submitted and registered under CRD42020225976 in PROSPERO 