Speed Up Your Cinching

You might not guess it, but focusing on these five nonabs muscles is key to a fitter, flatter core.

- Janet Lee

The tightest bellies aren’t formed simply by firming the four muscles that make up your abs. “Think back to those athletes’ bodies at the Olympics,” says Dixie Stanforth, Ph.D., a teaching fellow in the department of kinesiology and health education at the University of Texas at Austin. “One of the things that makes them look so good is that they don’t train muscles in isolation. They’re not doing abs-only moves. They’re using many muscles at once, because that’s how the body works best.” In other words, thanks to the domino effect, fine-tuning how much other supporting muscles pitch in during certain exercises can help you trim your waist. Meet five muscles that affect your belly, and find out how to get them to work as ab tighteners.

Neck flexor

Have you ever noticed that your chin juts toward the floor when you hold a plank? Or that your head seems to lead when you bang out crunches? “That means your neck muscles—specifically the sternocleidomastoid and scalene—are trying to power your abs,” says movement specialist Perry Nickelston, D.C., the author of the upcoming Stop Chasing Pain. To put the work back on your abs, pull your head in line with your shoulders and tuck your chin. And since the back of your neck is often tense and tight, release tension there before you do any ab work: Lie faceup on the floor for a minute or two with two tennis balls placed at the base of your skull on both sides of your spine.

Diaphragm