Yes, we all do crunches. Crunches, crunches and more crunches. I do them myself, and think very highly of them. But! If you'd like to change things up and work on sculpting your fancy torso in new way, give these skills a try.

• Prone pikes. Place your feet on a stability ball or on some Gliding Disks, with your hands on the floor in push-up position. Back flat. Lift your hips straight up to the sky while keeping your legs straight. Once you've elevated your hips as high as they'll go ... lower back to push-up position. Repeat at least eight times. Add one rep each day you do these. Very advanced!

• Front kicks. Stand with one foot in front of the other with feet shoulder width apart. Lift the front leg by the knee first, and follow to extend your foot up high. You'll engage your hip-flexors and rectus abdominus as you raise that leg up high. Kick within your comfortable range at first, but challenge yourself to kick higher along the way. The higher you lift your knee, the more you'll work your abs. Switch your stance and repeat on the other leg. Kick at least 20 times per leg. Beginner to advanced level exercise, depending on how high you kick.

Source