Weighted Sit-Up On Bosu
Your level of expertise will dictate how much weight to use. Beginners should start out holding a 10-pound plate, while advanced trainees can try this move with a 45-pound plate.
With your legs extended perpendicular to the floor, lower them down and to the side, a few feet left and right of center. Advanced trainees can try this move with five-pound ankle weights.
Your range of motion with this exercise will be relatively small. Lie on your side and lift your legs and shoulder girdle off the floor. Hold for a second at the top.
Harry Selkow is a trainer at Re-Active Gym in Pleasanton, CA