Try this core challenge to not only strengthen your full abdominal area, but these holds also allow you to breathe and relieve tention and stress. Do these for each side, left and right. Remember to breather.

Week 1 - kneeling side bridge / 2 sets / hold 30 seconds
Week 2 - kneeling side bridge / 2 sets / hold 60 seconds
Week 3 - Side bridge / 2-3 sets / hold 45 seconds
Week 4 - side bridge / 2-3 sets / hold 60 seconds
Week 5 - elavated bridge / 2-3 sets / hold 45 seconds

Kneeling side bridge: lye on your side and press up on your elbow while tightening your abs and breathing, leaving your knees on the floor. Reach a 45 degree angle with your body in line and hold this pose.

Side bridge: lye on your side and press up on your elbow while tightening your abs and breathing, this time taking your knees off the floor. You should have tight legs, buttocks, abs, chest, and head all in a row reaching a 45 degree angle with your body in line and hold this pose.

Elevate bridge: This is the most challenging move, using a bench, resistance ball, chair or couch, place your feet on the higher level (ex. bench) and while on one side press up on your elbow or for taller items, press and hold up with your hands. Do this while tightening your abs, body lines, and remember to breathe. Hold the angle with your body in line and hold this pose.