Rambam’s Timeless Wisdom- The Fourth Rule: Physical Activity

The muscles of the human body, which are responsible for movement, were created with a built-in mechanism requiring moderate activity in order to function properly. A muscle that remains unused for a long period begins to atrophy; whereas moderate use not only avoids damage, but renews its cells, revitalizes, and strengthens it. For this reason, one of the main conditions for maintaining physical health, as the Rambam (Maimonides) enumerates, is physical exertion. In his Mishneh Torah, in the Book of Knowledge, he writes: "Another general rule regarding health: As long as a person engages in physical activity and exertion, does not overeat, and keeps his bowels loose, no illness will come upon him and his strength will be reinforced. But whoever leads a sedentary lifestyle, avoids exertion, delays relieving himself, or has constipation- even if he eats healthy foods and follows all medical advice- his life will be full of pain and weakness."

By "engages in activity," the Rambam does not mean formal exercises as we know them today, but rather general bodily exertion from labor and effort. A person whose occupation requires physical effort may not need additional exercise, but someone with a sedentary job must dedicate time to physical activity. This doesn’t need to be excessive, but basic, intentional movement that engages the full body to keep it vital and energized for serving G-d.

The Rambam includes these health directives in his 14-volume work Mishneh Torah- a code of all Jewish law. He justifies this inclusion by explaining: "Being physically healthy and whole is part of the path of serving G-d. For it is impossible to understand or know anything about the Creator when one is sick. Therefore, a person must avoid anything that harms the body and accustom himself to practices that promote healing and health."

Everyday Opportunities for This Mitzvah

Many simple daily choices can fulfill this mitzvah. For example, when arriving early to a meeting, instead of racing to find the closest parking spot, one can intentionally park a bit further away to benefit from a short walk. Similarly, instead of waiting several minutes for an elevator to go up one floor, a wise person will take the stairs, especially when time allows.

In our technological age, where machines do so much of our work for us, it’s often not enough to rely on daily activities for physical exertion. We must create brief and consistent moments of movement each day.

At the same time, Judaism firmly rejects glorifying the body for its own sake or pursuing physical perfection purely for aesthetic goals. Such an attitude stems from falsehood and opens the door to indulgence and ego. A Jew should remember that the body will eventually return to dust, as stated in Pirkei Avot: "Know from where you came and where you are going...from a putrid drop, and to a place of dust, maggots, and worms."

Greek culture, which denied the soul's eternity, glorified the body as the ultimate ideal. From it came all forms of sport (named for Sparta, its origin), which focus solely on the physical and neglect the spirit. In contrast, Judaism promotes physical exercise only as a means to keep the body strong and healthy- a tool to house the soul and support its divine mission.

Rambam’s Guarantee

The Rambam concludes with a powerful promise: "Anyone who lives according to these guidelines, I guarantee that he will not suffer illness throughout his life until he grows old and dies. He will not need a doctor and will remain strong and whole- unless he was born with a weak constitution, already harmed himself, or there is a divine decree like a plague or famine."

Compassion Toward Others

It’s essential that a person committed to healthy living not become arrogant or scornful toward others who do not share the same awareness. Rather than judging, one should treat others with dignity and try, gently and humbly, to share knowledge when invited to do so.

This sensitivity is especially crucial when it comes to children. If a child feels left out because their peers eat unhealthy sweets and they are constantly denied, it’s wise not to restrict them completely. Instead, try to minimize the intake while offering healthy alternatives, without the child feeling deprived. For instance, if the child brings home an unhealthy treat from preschool, the parent can offer a healthier, more appealing substitute in exchange.

Similarly, when visiting others as a guest, one should not offend the host by rejecting the food served. It is usually appropriate to choose the healthiest option available from what is offered, even if it’s not ideal. Total abstention from certain foods can also be harmful. For example, avoiding fats completely may increase the risk of stroke, according to some studies. Others believe that consuming small amounts of “non-health” foods may actually keep the body’s detox system active.

An obsessive approach to health can become its own kind of illness. Excessive strictness and health anxiety can harm both body and soul. As Rabbeinu Bachya famously said, "Even in caution, do not overdo your caution."

One must strive for a balanced lifestyle that is healthy, joyful, and spiritually aligned. When needed, make compromises to preserve harmony with others, without violating principles of kashrut or risking serious health damage. Always remember: a healthy body is a vehicle for a healthy soul.