this is good for general core strength:
It's the same type of thing I've been doing for 4+ years and I have better core strength than any of the guys on my team who outweigh me by 50 lbs or more. I also do a ton of medball...entered a SPARQ training test at a showcase and was ranked 1st out of 150+ HS players in the rotational powerball throw. Make sure when you do the medball you are throwing it AS HARD AS YOU CAN, it's about becoming EXPLOSIVE
Jo(h)n Doyle has a program called Unbreakable Abs which I'm looking into and is supposed to be great, I'll get back to you when I find out more.
Also can do some weighted abdominals...Russian twists with dumbbell, hanging leg raises, russian twists with barbell, etc.
All great exercises, and as a bonus if you keep your diet super clean and get your body fat down a bit you'll start to look super ripped. :lol:
hope this helps