Our brains don’t like change. That is a mouthful. The facts seem to indicate that it takes about a month to actually change a habit, or get into one. Like walking, and being more active. Or eating healthy. All of these are changes that take a while to get used to. And the brain will at first resist the change. It’s a defense mechanism!
Perhaps the best advice I have heard is to start slowly, don’t overdo, and gradually build up, but it seems harder to do it the right way! Some people just go all out, but there are dangers associated with dramatic changes. As always, you never begin anything until you tell your doctor what you want to do. That’s important.
Ask you doctor. Start slowly. Make changes. And your mind will follow.