Your body is not your own, and you are not free to neglect it.

Most people handle their body for one of three reasons: how it looks, how it performs, or how it feels. None of the three is wrong, and nothing here is against performing well or feeling good. But each makes the body its own end, and none of them has an answer for the day you look worse, perform worse, and feel worse than you did a year ago.

The sixth commandment gives the better reason. It forbids murder, and the Larger Catechism reads the whole duty out of it: careful study and lawful endeavor to preserve the life of ourselves and others, a sober use of food, drink, medicine, sleep, labor and rest, and a refusal to neglect the ordinary means by which a life is kept. Caring for your health is not vanity and it is not a hobby. It is the keeping of a life you were given, for the glory of the one who gave it.

Your body responds to what you actually do, not what you hope, and motivation is a poor foundation for anything that has to happen two hundred times a year. What holds is structure: a time already blocked, clothes already out, a standing commitment with another person. Make the right thing the default and you stop spending resolve on a decision you already made.