Adolescents who walk to and from school have higher overall physical activity levels throughout the day compared with those who travel by car, bus, or train, a British Medical Journal study has found.

The study, published online by the BMJ today, suggests that how children travel to and from school seems to affect overall physical activity and that understanding these findings is important for promoting healthy school and transport strategies.

Researchers measured moderate to vigorous physical activity among 92 pupils aged 13-14 years, from four schools in the Edinburgh area of Scotland. Pupils were asked to wear accelerometers (an instrument used to measure vertical movement) throughout the day and were surveyed about their journey to school.

Pupils were split into three different groups: those who travelled both ways by car, bus, or train; those who walked both ways; and those who walked one way.

Pupils who walked both ways accrued the most minutes of moderate to vigorous physical activity throughout the day, followed by those walking one way. Moderate to vigorous physical activity outside school hours was significantly higher among those pupils who walked both ways than among those using a car, bus, or train.

In all, 87% of pupils using a car, bus, or train, accumulated an average of 60 or more minutes of moderate to vigorous physical activity on weekdays compared with 90% of those who walked one way and 100% of pupils who walked both ways.

Similar results have been reported for 10 year old children, although among five year olds, mode of travel to school did not significantly affect overall physical activity, suggesting that walking to school may be more effective for older children.

Reasons for increased physical activity may include differences in appreciation of activity, and walking in the morning may stimulate further activity, suggest the authors.

Understanding these differences would enhance health promoting school and transportation strategies, they conclude.

(GB/SP)