Exercise, yes, that godawful word. So far I've been doing this (even though it says 30 reps by 30 times, I call horse manure on that and just do each exercise 30 reps each):
YouTube - 300 Spartan Workout 2
I've been happy with how I feel overall (sans the fact that I've been doing it at 3am every 5 days while i work overnights), but the definition in my stomach muscles isn't coming through as expected.
How long does it take for results like that to occur?