im not doing it to become arnold.. and i do parkour shit all the time, not recently cause i tore the ligaments in my right foot doing a backflip 180 off a buststop roof.. and that was october 30th : (
its pretty much healed now.. i also like to trampoline when i can, if you continuously try spinning tricks with different axis's it can be a very good workout. i ride my bike all the time too.. mostly downhill and freeride, which are as good as an offseason sport as you can get to skiing.. cept maybe lollerblading, but that aint as cool!