Kids who exercise before school were more able to focus in the classroom said a new study.
Researchers in Denmark found that children who walked or rode their bikes to school performed better than those who took public transport or were driven by their parents.
The study used a survey of nearly 20,000 students between the ages of 5 and 19.
The students were quizzed on their exercise habits and then given a concentration test.
"The exercise one uses to transport oneself to school is reflected in the level of concentration one has circa four hours later," said study co-author Niels Egelund, reported AFP.
"As a third-grade pupil, if you exercise and bike to school, your ability to concentrate increases to the equivalent of someone half a year further in their studies."
Previous research had focused on whether or not children had breakfast and its effect on concentration.
Yet, in this study, it was found that breakfast was not the main determinant but rather exercise had a greater impact.
"The results showed that having breakfast and lunch has an impact, but not very much compared to having exercised," Egelund told AFP.
The results undoubtedly apply both to focusing at school and at work.
LiveStrong.com has some tips for working out in the morning.
They include laying out your clothes and preparing your lunch the night before as well as skipping public transport and walking to school or work.