I find that whatever music I use for working out works best. I guess there's some link in my brain - the meditative state you get into when you exercise where it's just you, the pain and the music puts your brain into a highly focused state. I discovered that after a while of doing this, whenever I listen to my exercise playlist, it puts me into that same focused state regardless of whether I'm exercising... and I now use the same playlist for highly focused/fast pace programming. Of course it helps to maintain the link between that kind of music and focus if you regularly use it for exercise.

YMMV