Barbell roll-out

Directions:

For this exercise, you will need to get into a pushup position, but instead of having your hands on the floor, you will be grabbing onto an Olympic barbell (loaded with 5-10 lbs on each side) instead. This will be your starting position.
While keeping a slight arch on your back, lift your hips and roll the barbell toward your feet as you exhale. Tip: As you perform the movement, your glutes should be coming up, you should be keeping the abs tight, and should maintain your back posture at all times. Also, your arms should be staying perpendicular to the floor throughout the movement. If you don't, you will work out your shoulders and back more than the abs.
After a second contraction at the top, start to roll the barbell back forward to the starting position slowly as you inhale.
Repeat for the recommended amount of repetitions.

Caution: This is a challenging exercise for people with healthy backs.

Variation: This is an exercise that, just like the push-up, can also be done on the knees for less advanced athletes.