The slow and controlled pulse of this exercise keeps the abs engaged, and adding the weight of a medicine ball or dumbbell kicks your abs into high gear and increases the burn. Choose a weight between five and four kilograms.
- Begin lying on your back with your legs in the air and toes toward the ceiling, while holding the medicine ball over your chest with straight arms. Engage your abs (bring your navel in toward your spine) to press your lower back into the mat while lifting your head, neck, and upper back off the mat.
- Exhale and round your lower back so the bottom of the pelvis raises as you lift your upper body an inch higher off the mat. Aim the medicine ball toward your ankles as you perform this double crunch.
- Inhale and lower your pelvis and upper back an inch toward the floor.
Image Source: Sam Kang