There are conventional things that you're going to get a lot of comments about. My conventional thing is running. The hacky part is the endorphins you get.[1] Other than the hack, you constantly set goals and achieve them, it makes you feel good about yourself. Micro goals like "I'll make it to the end of the street without stopping," and larger goals like "I'll run 5 miles today." Positive reinforcement during the run, large feeling of accomplishment after.

[1]https://www.webmd.com/depression/guide/exercise-depression#1