I've tried running, lifting and other training routines and I just can't keep it up. I don't have the discipline to keep up something I find so boring. No disrespect meant to lifters&runners, quite the contrary, I envy you guys.

Somehow though, cycling does it for me. I can go fast. It can take me places conveniently. I can do it out there in nature when I get out of the city on weekends. And, it fits in with my need to tinker with mechanical stuff :)