Forget sit-ups and crunches — I added this abs exercise to my workouts, and my core is still trembling

A photo of a man doing high plank with leg lifts.

I'm always hunting for abs exercises that get my core trembling, but they need to actually produce results over time, not just a burn at the time. For that reason, I started introducing the three-legged plank and tiger curl exercise combination to my abs workouts, and I don't regret it for a second.

This move, as the name suggests, combines a three-legged plank (challenging enough on its own) with a tiger curl, which involves drawing the knee under the body toward the nose. You'll work one side at a time, testing anti-rotation, balance, stability and strength.