A year-long study at the Institute of Exercise and Health Sciences, University of Basel, in Switzerland has found that children given more exercise time at school, in dedicated lessons and throughout the day, as well as ten-minute exercise homework, were fitter and put on less weight than others.
Previous studies have suggested that children simply compensate for the extra sport at school by being more sedentary for the rest of the time.
Research published in the British Medical Journal online compared the health of children given extra exercise with those on the standard three lessons a week programme.
The children aged seven and 11 who did the extra exercise could run the equivalent of 20 seconds faster, their body fat as measured by skinfold thickness was 2mm less and their body mass index improved.
Whilst overall daily physical activity and quality of life did not change significantly and the effects were small, the findings still have important public health implications the researchers said.