Use these two exercises as a progression from the ab wheel. The videos don't do them justice. You've got to try them to understand it.
Keep these in a low to moderate rep range, multiple sets of 5-8 reps. Going high rep on them can make the low back kick in. But you've been warned: This will leave even veteran lifters shaking like a leaf on a tree.
Ten years ago, most people who trained with weights had never heard of a "strength coach." Oh sure, there were sports coaches who worked with athletes on performance. And there were famous bodybuilders who theorized on hypertrophy methods in the magazines.
Sure, this article is about a sometimes boring, often unsexy topic: injury prevention. But unlike most articles on the subject, this one contains plenty of info that'll help any lifter, regardless of whether his joints are bulletproof or not.