Miburo

400 meter dash is just sprinting, I'd assume?

If so, if it were me I'd go for pure strength gains and explosiveness. Muscle mass isn't really an issue for sprinters, I would think. It's really only an issue for sustained long distance shit. I would think you'd want as much power as possible, and just be able to go all out for a relatively short amount of time with quick recovery. Strength training (Starting strength is a great workout for good all around gains, pirate bay the dvd or some shit if you have access to a decent gym) and HIIT cardio (You can do it with lots of shit, just google it) does that. Same shit I do for battling, pretty much. You want to be like a goddamn predator. Cheetahs and shit fucking sprint. Gazelles, or whatever the fuck cheetahs eat, are the long distance dudes. No one wants to be a goddamn gazelle, unless you do marathons or cross-country or whatever.

Makes sense to me. And it works great for manly grappling.