A hobby has many benefits, not just for your mental wellbeing but also for your physical fitness. Exercise is the obvious #1 health benefit of any hobby. Second is a hobby’s social benefit. There are clearly psychological benefits of interactions in social groups, so hobbies will get extra credit if they lead to interpersonal meaningful interactions. Third is the need to think, either analytically, computationally, or just stretch you to think and learn.
Dancing: Ballroom, swing, whatever the style, dancing rates high on all of the criterion above.
Gardening: If you like working in the dirt, reaping the benefits of your toils in the kitchen or as a favor to the eye in the yard, this is a hugely popular and healthy option for exercise.
Golf: Lower on the list than you might think, because of the big time commitments, cost, and golf only gets credit if you don’t use a cart. Still, if walked briskly, done regularly, and enjoyed, it is a healthy choice.
Cooking: Included here because almost anything you cook has the potential to be a healthier meal than something out of a box, can or at a restaurant.
Horse-back riding: This hobby can bring you closer to nature, and it’s something you can do alone or with your friends. It’s a great way to spend a regular weekend away and it’s great full body exercise.