lol
that's the right principle certainly - interval training
i do it in a little less hardcore, non-army kind of way, but it should hurt a little bit or you're not doing it right. I think it's half physiological, i.e. your body gets used to big demands being placed on it, and half psychological, i.e. your mind gets used to the idea that you have the reserves for one more sprint.
i do this:
1) sprint 10 secs
2) jog 15 secs
3) walk 20 secs
4) see (1)
mind you, having a fucking crazy ex-army type screaming at you also works wonders I believe, maybe you could hire one ?
