If you want rock-hard abs, try this cutting-edge core complex from fitness expert BJ Gaddour, CEO of StreamFit.com. With this routine, you'll use a Swiss-ball to do three consecutive core exercises for 30 seconds each -- a total of 90 seconds. Then you'll rest for 90 seconds. That's one round. Repeat until you’ve done a total of 2 to 4 rounds. You'll not only work your six-pack muscles, but your entire core -- from your shoulders to your hips. And for a complete eating plan that'll give you abs that show, check out Travis Stork's Lean Belly Prescription.