8 Trainer-Recommended Isometric Ab Exercises to Light Up and Completely Exhaust Your Core

"Oftentimes, simple is better," said Giancarlo Regni, ACSM, and Tyler Curtis, NSCA, of G-Strength. The side plank, they said, is a simple effective isometric move that targets your obliques and helps to stabilize your lower back.

• Balance on your right hand and the outside edge of your right foot, with your body in one straight line. To modify, stagger your feet and bring your top leg forward.
• Hold for 30 seconds on each side to complete one rep.