"In Pilates, the core isn't just about your abs — it's your whole midsection, including the back side! These next couple of moves target your posterior (back side of the body) chain," Jetter says.
Start by lying on your back with your knees bent and feet flat on the floor, hips-distance apart. Lengthen your arms by your sides and press your palms firmly into the mat.
Inhale to prepare, and exhale as you start from your tailbone and peel your spine off the floor one vertebrae at a time. Stop at the top when your body makes a flat line from the front of your rib cage to the fronts of your thighs — be mindful not to arch your back and let your ribs fan out.
Inhale at the top, and exhale again as you start from your upper back and melt your spine back into the floor one vertebrae at a time.
Repeat 20 times.
"By articulating through the spine, you're continuing to involve the deep abdominal muscles while now also involving the glutes (booty) and hamstrings (back of the thighs)," Jetter says.