Seneca, Moral Letter 15, “On Brain and Brawn”

“Now there are short and simple exercises which tire the body rapidly, and so save our time; and time is something of which we ought to keep strict account. These exercises are running, brandishing weights, and jumping, – high-jumping or broad-jumping, or the kind which I may call, "the Priest's dance," or, in slighting terms, "the clothes-cleaner's jump." Select for practice any one of these, and you will find it plain and easy. But whatever you do, come back soon from body to mind. The mind must be exercised both day and night, for it is nourished by moderate labour. and this form of exercise need not be hampered by cold or hot weather, or even by old age. Cultivate that good which improves with the years. Of course I do not command you to be always bending over your books and your writing materials; the mind must have a change, – but a change of such a kind that it is not unnerved, but merely unbent. Riding in a litter shakes up the body, and does not interfere with study: one may read, dictate, converse, or listen to another; nor does walking prevent any of these things.” (Seneca, Moral Letter 15, “On Brain and Brawn”)