Instructions: For a full core burn-out, choose three or four moves from the list below. Perform as many reps as possible ...

Then what we're going to do is leg lifts. You go right ... and then circle in and then circle out. So, that's a great way to work your lower abs. More from Science ...

Circle your arms out to the sides and ... your hand perpendicular to your body, and your legs stacked. Engage your abs and the right side of your waist. Lift your hips so your body forms a ...