WHY: This exercise will help you learn to activate your glutes. It is a progression of the single leg bridge with your leg supported and will further challenge your glutes as well as your core stability.
HOW: Lift your opposite knee and ankle up in the air - keep it there. Next tighten up your stomach first, then your glutes. Then, drive your heels into the ground and lift your hips up. Do not let one hip rise before the other.
FEEL: You should feel your stomach muscles and glutes work to control this motion. At no point should you feel your low back muscles doing the lifting motion.