To work your entire core, elbow plank is an effective exercise.
- Lie on your belly, with your elbows close to your sides and directly under your shoulders. Place your palms down with your fingers facing forward. Engage your quads to extend your legs, and draw your naval toward your spine to engage your abs.
- Now press your feet and forearms into the floor and lift your body off the ground. Try to keep your torso and legs in one straight line, with your back flat. Hold for five or more seconds, and then slowly release back to the ground.
- Repeat a total of five times.