Western culture measures strength in muscle. When you ask any American, even young boys or girls, to "show me how strong you are," 99% of the time they'll lift up their arms and curl their biceps.

But big arms don't translate into health. Nobody has ever died from bicep problems! According to Eastern Philosophy and Internal Martial Arts traditions, true strength lies in the abdomen. Specifically, in the area between the bottom of your ribs and your hips, where you don't have much skeleton for support. Almost all of your internal organs are seated here, surrounded by many protective layers of muscle and fascia. When you ask about strength in an Eastern culture, people slap their bellies, as if to say, "Look how strong and protected my organs are!"

So how do you strengthen this area? Well, most people would tell you to do more crunches and sit-ups! While these exercises are good, they only touch the tip of the iceberg. The muscle and soft tissue of the abdomen doesn't just run up and down. It goes side-to-side and diagonally as well. You'd have to do a dozen different types of crunches just to exercise all these muscles!

In my classes and online courses, it's hard to find an exercise that doesn't increase your core's strength or flexibility. But for the beginner, there is one exercise I would suggest. I call it "Empty-Full Moon." It is simple to learn, but hard to master.

Here's how you do it: when you breathe in, pull your stomach and lower back toward each other with about 80% effort. Don't just suck in hard, be mindful. Pull your belly button straight backward and feel your lower back move just a little bit in. When you breathe out, do the opposite. Push out with your back and belly with 80% effort. If you're really good, you can incorporate Wing Breath into this exercise as well.

And don't worry, this won't make your belly bigger!