Most people train their abs for vanity (hello six-pack!), but having a strong core is essential to doing every day activities, even walking. A strong core (with or without a six-pack) is the secret to having great posture, running faster, and preventing injuries like lower-back pain. Improve your core strength (and get sexy, toned abs while you're at it) with this twist on the classic plank.
Here's how to do it:
Start resting on all fours.
With your palms flat, raise up off your knees onto your toes. Keep your hands directly below your shoulders.
Contract your abs to keep yourself up and prevent your bottom from sticking up. Remember to keep your belly button pulled in.
With your head and spine in line, keep your back flat - don't let it curve. Picture your body as a long, straight board.
With control, slowly tap your left knee to the ground without moving your hips. Lift your left knee back up, returning to the starting position. Repeat the same movement with the right leg. This completes one rep.
Complete two sets of 10 reps.