A strong core is the foundation to a strong body. Think about it: A tree would fall if its trunk wasn’t solid and stable. Doing core work isn’t just about your middle, either. Having a strong core will make you a better runner, surfer, or yogi (or whatever activity you like to do) while improving your posture and balance. Working your core can also protect you from low back pain — and yes, it’ll tone your abs, too. One of the best core exercises out there is the plank. “It forces you to stabilize your body, engaging your entire core — not just the exterior abs that you see in the mirror,” says celebrity trainer Anna Kaiser, founder of AKT InMotion studio in New York City. This means your obliques, or all-around abs (where you’ll find those lovehandles), and transversus abs (the deepest layer) will tighten up. Plus, you’ll work your shoulders and your legs at the same time. Here, Kaiser has created an easy-to-follow 30-day plank challenge that will get you results quickly. You’ll start by planking at an incline (try leaning against a wall, chair, or the back of your couch), which is easier for beginners. Then, as you get stronger, you’ll move to the floor and work your way up to holding a plank for three full minutes. If it’s too difficult for you to do the plank with your palms flat on the ground, you can modify it so you’re resting on your forearms. Just make sure you don’t hunch or strain your shoulders. Your goal is to maintain proper form (don’t crane your neck or let your hips sag) while holding up your own body weight. “The hardest part about planking is committing holding still until the end,” says Kaiser. Want to make sure your plank form is on point? Check out our 30-Day guide to the fundamentals: Source