A cross-curricular physical activity intervention to combat cardiovascular disease risk factors in 11-14 year olds: 'activity knowledge circuit'. - Knox G; Baker JS; Davies B; Faulkner S; Rance J; Rees A; Morgan K; Thomas N; Knox, Gareth; Baker, Julien S; Davies, Bruce; Faulkner, Susan; et al. (BMC Public Health, 2009)