I'll throw in my vote for actually liking the exercise I do, which is mostly sprints and weightlifting. During school it was my meditation. After working on oth

I'll throw in my vote for actually liking the exercise I do, which is mostly sprints and weightlifting. During school it was my meditation. After working on other, uncertain things for long enough I need to be able to hone my own will, struggle for my own sake, and yes, I do get the endorphins.