Dolphin Dive

This move may incorporate a pose that seems familiar, but it's far from your typical plank. The yoga-inspired exercise keeps you constantly moving—not only to prevent boredom, but also to work a large percentage of the muscles that make up your core, including those in your back, such as your erector spinae. "You have to train all 360 degrees of your core to gain proper strength and function," McGee says.

How to do it: Get in a low-plank position on your toes and forearms, elbows stacked directly underneath your shoulders. Then press your hips and shoulders back toward your feet and pike your hips up in the air so that your upper arms are diagonal to the floor and your lower arms are still flat on the ground. This is the starting position. Next, dive your chest down and forward, lowering until your body is in a low plank, forming a straight line from head to heels. Pause for three seconds, then slowly reverse the movement to return to the starting position. Do two to three sets of six to eight reps.

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