Well you shouldn't be smoking either. Why not just enjoy a box of chocolate instead?
Lol, I even wrote
just in anticipation of that comment 
You could try running. Running makes everyone feel good and it has no negative side effects
Running always makes me feel bad. Also, you can get shin splints. God, I hate getting shin splints, they hurt like a bitch. Oh, and the muscles in your leg can tighten, causing bone fractures. Oh, and it contributes to arthritis because of the impact damage from your weight colliding with the ground repeatedly. That's why we have elliptical machines though.
Running is good for you, of course, but it definitely wouldn't be what I do for fun 