Tighten and Tone Thursday-superman for a super core

My core is always my trouble area these days.  I'm constantly looking for ways to flatten and challenge my core muscles, including my lower back.  A strong core and back help with posture, over all strength and make you look slimmer.  One exercise to help you achieve your new core is the superman.  Start laying on your stomach with your arms stretched over your head.  Next, left all four limbs off the floor and tighten those abs and glutes.  Hold for 5-25 seconds depending on your ability level.  Lower all four limbs to the start position..  Repeat!  Try doing this 10 times, then 15, then 20, etc.  You may feel a little silly doing this exercise, but it is worth it.