PT - JOURNAL ARTICLE AU - J Dollman AU - K Norton AU - L Norton TI - Evidence for secular trends in children’s physical activity behaviour AID - 10.1136/bjsm.2004.016675 DP - 2005 Dec 01 TA - British Journal of Sports Medicine PG - 892--897 VI - 39 IP - 12 4099 - http://bjsm.bmj.com/content/39/12/892.short 4100 - http://bjsm.bmj.com/content/39/12/892.full SO - Br J Sports Med2005 Dec 01; 39 AB - It is not clear whether the global increase in weight problems in children is the result of excessive energy intake or decreasing energy expenditure. Methodological limitations have made it difficult to analyse. There is evidence that at least part of the problem may lie with increasing energy consumption, but it is important to examine the other side of the energy equation also. However, it is not possible to conclusively describe physical activity trends because of the absence of suitable baseline data. One solution is to summate all available evidence in as many areas of daily activities as possible and then draw tentative conclusions. This review summarises available trend data on direct representations of physical activity in a range of contexts, together with indirect measures such as sedentariness, fitness, and attitudes. The conclusions drawn are: physical activity in clearly defined contexts such as active transport, school physical education, and organised sports is declining in many countries; young people would like to be active but are often constrained by external factors such as school policy or curricula, parental rules in relation to safety and convenience, and physical environmental factors.