Getting schoolchildren to walk or run a mile every day increases their physical fitness, but there is little evidence it improves academic performance.
That is according to just-published research from Ulster University (UU) funded by the Education Authority (EA).
Many schools in Northern Ireland take part in the daily mile, which involves children taking a 15-minute break from class to do physical activity.
It was originally introduced in Scotland a decade ago.
The initiative is in addition to normal physical education (PE) lessons.
