This review was undertaken to address what is known about the barriers to, and facilitators of, physical activity amongst children aged four to 10. It aimed to bring together the findings from 'qualitative' as well as 'quantitative' research on these barriers and facilitators. This systematic review was published by EPPI-Centre in 2004. Systematic reviews aim to find as much as possible of the research relevant to the particular research questions, and use explicit methods to identify what can reliably be said on the basis of these studies.