New knowledge in biology accumulates fast. This has great implications, for example, for our views of learning. Brain research, as well as research in the new field of epigenetics, have been very intense during the last few decades, and will doubtless influence our view of learning. It is important to follow the development in biology, derive advantages from new insights, and to consider changed practices at school. This paper is an example of how an increased amount of physical education in the school timetable could increase performance in theoretical school subjects. This relation is discussed in the light of the recently discovered epigenetic mechanisms. Studies have revealed epigenetic modifications in the brain cells during learning. Learning, combined with physical activity, has revealed increased epigenetic modifications. Thus, it has been speculated that epigenetic mechanisms might explain improved results in theoretical subjects due to physical activity. This ought to have implications for the school timetable, and lead to more physical education at school. It is discussed that one of the easiest ways to improve results in theoretical school subjects could be to increase the amount of physical education in the school timetable.