Front Plank

This is a great exercise to help strengthen your core.  To begin, lie on your stomach, elbows tucked into your sides and under your shoulders.  Palms should be face down.  Tighten your abdominal muscles.  Tuck your toes and tighten your thigh muscles (to help straighten legs). 

Keeping abdominal area and legs tight lift your torso and thighs off the ground. Your body should remain in a straight line (Do not allow sagging to occur in your low back or upper body).  Elbows should be directly under shoulders.  Hold for 15-30 seconds.  Increase this time as you become more fit.