An advanced calisthenics move (that's a blend of bodyweight strength and gymnastics, for the unintiated: think push ups, pistol squats and pull ups and you've got the gist), the L-sit can be performed ...

These expert-backed Pilates moves target your deep abs to tighten your belly, improve posture, and strengthen your core.

If you’re trying to build core strength and don’t really like doing crunches, because you find it hard to engage your core, ...