If you have the space in your workout spot then try and incorporate the exercise ball into your routine, and you’ll challenge your stability, which makes every muscle work extra hard. First-timers should choose a large, firm ball, and progress to a squishier one, which is inherently less stable and makes each move feel even more difficult.

Superman to Shoulder Pullback: Lie facedown on the floor, and grasp the ball between your ankles. Your arms should be outstretched overhead with your palms facing down and your shoulders away from your ears. Then, exhale and engage your butt as you simultaneously raise the ball up toward the ceiling, and lift your chest and arms up off the ground. Keep your legs and the ball in the air as you squeeze your shoulder blades together and drive both elbows back toward your sides. Pause, then release your hands to the starting position. With control, lower your upper and lower body to the ground. That’s one rep.

What it works: Your butt, hamstrings, shoulders, and lower back.

V Sit-Up with Squeeze: Begin on your back with your legs outstretched. Hold the ball with both hands and extend your arms overhead. Brace your core and squeeze the ball as you simultaneously raise your legs, the ball, and your shoulders a few inches off the ground. Exhale as you lift your legs and arms to meet in the air. Then, squeeze the ball between your ankles as you let go of the ball with your hands, and simultaneously lower your legs and arms until they both hover just above the floor. Your lower back should stay pressed against the ground the entire time. Pause, then lift your arms and legs again, this time passing the ball from your ankles to your hands. With control, lower your arms and legs back to starting position. That’s one rep.