A recurrent theme throughout Galen’s writings on how to lead a healthy life is the importance of moderation. Diet is one very important part of a well-balanced regimen, but so too is activity. Galen was a proponent of exercise and differentiated this activity from simple movement: exercise is movement that causes faster breathing. Galen saw two main benefits from exertion, “one, for the evacuation of excrement, the other for the production of good conditioning of the firm body parts.” He also believed exercise improved the strength of organs, aided metabolism, and assisted with the distribution of nutrition from food. He wrote with admiration about people who had maintained an active lifestyle into old age: a fellow physician, Antiochus, walked a half-mile from his house to the Roman forum every day, and continued to visit patients by foot well past the age of eighty. Exercise could be a part of daily life such as wood chopping, digging, rowing, and barley grinding. Other forms of healthful exertion that were a part of work included house construction, bronze working, plough making, and shipbuilding. Or one could work out by taking exercise deliberately, including such activities as running, shadowboxing, wrestling, and ball playing. Aristocratic activities could count as exercise too: hunting, fishing, military training, and even being carried in a bouncing carriage.
Galen’s advocacy for exercise and admiration of his active colleague contrasts with his contempt for athletes, whom he criticized for training in order to compete in competitions rather than for health. His position went against prevailing celebratory attitudes toward athletics, but in Galen’s view athletic preparation was excessive—it did not follow the guiding principle of moderation—and could actually harm the body. In his text An Exhortation to Study the Arts, he emphatically explains how excessive exercise for sport was counterproductive, even damaging.
For Galen, intellectual pursuits were activities superior to struggling in the gymnasium and disfiguring the body. He was not against exercise with purpose at the gymnasium, he just recommended that it be done in moderation. His ideal workout was with a small ball, and he devoted an entire treatise to the topic in Exercise with the Small Ball:
This text was addressed to the elite—not a readership that toiled in the fields—so this form of full-bodied exercise suited his audience’s lifestyle.
It was not only exercise but all bodily activities—from bathing and massage to sex—where moderation was key. Although Galen wrote less on the topic of bathing than some other Roman writers, he was nonetheless familiar with the specifics of its culture in Rome.
We know that the physician visited the public baths himself, and that he also recommended bathing and massage as a treatment to some of his patients. Galen sometimes prescribed a certain temperature of water or specific hot springs—the Aquae Albulae or the Aquae Domitianae, for example—but warned about possible side effects from too much bathing. While he certainly saw its salubrious effects, he also cautioned that taken to an extreme, excessive bathing could cause soft and flabby flesh, and lead to the types of diseases one found in women.
Galen knew that sex, perhaps even more than bathing, was pleasurable, but he argued that balance was necessary with this activity too. He believed that sexual release was healthful (and the retention of semen deleterious), and that intercourse was necessary for the continuity of humanity. However, he also warned that it was bestial to be preoccupied by sex.
Galen’s discussion of sex and its place in a healthy regimen, in his text Keeping Well, is not moralistic, and he focuses on how to restore the elemental and humoral balance following intercourse; his addressee is male, but, nevertheless, there is no single recommendation for all men: an individual’s postcoital cooling needs may vary.