The Undisputed Best Ab Moves, According to Pilates Instructors

"My favorite at-home Pilates abs workout without a machine is, hands down, [doing] planks!" says Nwando Emejulu, a certified Pilates instructor at New York Pilates. "I love to start with a forearm plank."

1. Balance on your forearms and toes with the body in one straight line, elbows directly under your shoulders. (To modify, drop your knees to the floor, maintaining a straight line from shoulders to knees.)
2. Engage your core, pulling your abs in and up.
3. Hold for 30 seconds.