The Suck-in-Your-Tummy Muscle

You ever play that game as a kid, where you stick out your tummy really far, then suck it in so tight that your ribs stick out?  We would complement that trick by saying "Before. After." - like in the weight loss commercials.  As teen vanity set in, I learned it isn't so bad to have a nice looking slim tummy.  Now, for decades I've been telling people this little discussed secret of body shaping, "Stand up straight, pull your shoulders back slightly, and use the suck-in-your-gut muscle." It's so easy, and it really works, when combined with other healthy practices.  Sometimes I see people who look pretty good, and think, "If they would only adjust their posture, they would look great."