Mens sana in corpore sano

Mens sana in corpore sano is a Latin phrase, usually translated as "a sound mind in a sound body". In the western world, the phrase is widely used in sporting and educational contexts to express the theory that physical exercise is an important or essential part of mental and psychological well-being.

The phrase comes from Satire X of the Roman poet Juvenal (10.356). It is the first in a list of what is desirable in life:

Traditional commentators believe that Juvenal's intention was to teach his fellow Roman citizens that in the main, their prayers for such things as long life are misguided. That the gods had provided man with virtues which he then lists for them.

Over time and separated from its context, the phrase has come to have a range of meanings. It can be construed to mean that only a healthy mind can lead to a healthy body, or equally that only a healthy body can produce or sustain a healthy mind. Its most general usage is to express the hierarchy of needs: with physical and mental health at the root.

An earlier, similar saying is attributed to the pre-Socratic philosopher Thales:

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