To achieve a cinched waist, it’s important to target all of your core muscles. This move in particular is fantastic for working out your obliques (those ab muscles on the side of your body.) Learn how to do Cross-Leg Diagonal Crunches with the help of Health's contributing fitness editor, Kristin McGee.

 

Here’s how to do it: Lie down on your back. Bend your knees, place your feet flat, and shift your hips over to the right. Then extend both legs straight in that direction. Take your left leg, cross it over your right leg. With your hands behind your head, crunch straight up to the ceiling. Go for 50 reps on that side and lower down. Then reset and do 50 more reps on the other side.

Trainer tip: Try to really scoop up your abs and get your shoulders off the mat.

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