A tight, defined core is more than just for show. In fact, it serves as the power center of your whole body, so a good core workout should hit every part of this complex muscle group. 

Encompassing the rectus abdominis, transverse abdominis, internal and external obliques, multifidus and erector spinae, your core overlaps with every other major muscle group. It works synergistically to stabilize you when you’re doing squats, deadlifts, presses and other high-intensity compound exercises, and it engages during every twist and turn you make throughout the day.

Because the core has to both look great and deliver ample strength and endurance whenever needed, the ideal core workout will include numerous angles of attack. That’s the approach of this routine. Requiring only a medicine ball, exercise band and Swiss ball, you’ll work your way through a five-step, circuit-style core workout that hits the lower abs, upper abs and rotational muscles, as well as the whole complex via isometric holds. Master these moves, and you’ll transform your core into an unstoppable powerhouse.

The 5-Move Hard-Core Workout

Do the following circuit three to four times through. Catch your breath for one to two minutes between rounds while only resting minimally when switching between exercises within the circuit.

Exercises

Medicine-Ball Reverse Crunch

Lie on the floor with your hands at your sides and angled out about 45 degrees from your body for balance. Elevate your legs off the floor, bend them to 90 degrees and place a medicine ball between your knees, squeezing your thighs together to hold it in place. Flex your abs to bring your knees toward your chest, allowing your glutes and lower spine to curl off the floor. Squeeze for a one-count in the fully contracted position, then lower your glutes back to the floor. Repeat for reps.

Pro Tip: Ready to get really hard core? Add a drop set to your final set of reverse crunches. First, go to momentary muscle failure with the ball between your knees, then quickly put it aside and continue with regular reverse crunches until you reach failure again.

Resistance-Band Crunch

Anchor a band to a sturdy object and lie faceup on the floor with your head nearest the anchor point, far enough away that the band will be taut when you grab each end of it. Your knees should be bent and your feet planted. Hold one end of the band alongside each ear, palms facing in, elbows pointing forward, and slowly curl your upper body off the floor, feeling the resistance of the band as you raise your shoulder blades. Think about shortening the distance between your pelvis and lower rib cage by contracting your abs as strongly as possible. Hold the top for a one-count, then slowly lower yourself back to the start.

Pro Tip: As with reverse crunches, you can get hard core here, too, by adding a drop to the last set. First, go to momentary muscle failure holding the band, then let it go and continue with regular crunches until you reach failure again.

Bridge to Crunch

Start in a bridge position — that is faceup with your feet planted and legs together, your knees bent to 90 degrees, and your hips elevated so only your head and shoulders are in contact with the floor. Your arms should be on the floor with your elbows straight. (If you can touch your heels with your hands, you are in a good position.) Hold the bridge for a five-count, then lower your hips slowly to the floor. Next, put your hands loosely behind your head and perform a crunch. Return to the bridge position and repeat the sequence.

Pro Tip: To engage the muscles of your posterior chain, think about “pushing” your heels into the floor while at the top of the bridge.

Medicine-Ball Russian Twist

Sit on the floor with your upper body and lower body elevated as you balance only on your glutes, holding a medicine ball in both hands directly in front of your chest with your elbows bent. Twist your body in an explosive manner to one side to touch the ball down to the floor, then quickly lift it up and bring it around to the other side to touch down again. Alternate at a controlled but brisk pace for reps — one “twist and touch” to each side equals one full rep.

Pro Tip: If you’re having trouble bringing the ball all the way to the floor, don’t fret — the touch down isn’t nearly as important as the controlled, core-engaging twist. You can simply bring the ball all the way to one side so that it’s next to your hip, but do not put it down to the floor, during your reps.

Stability-Ball Plank

Assume a plank position with your hands on a stability ball, about shoulder-width apart and palms aligned under your delts, legs together with your toes on the floor. Your body should be straight from head to heel. Hold this position, flexing your core to keep your hips from collapsing, for 30 seconds. Once you master the move, start working toward 60-second holds, increasing in five- to 10-second increments over time.

Pro Tip: Don’t have a stability ball? This exercise can be done on the floor, of course, or you also can grab the same medicine ball you used for your reverse crunches and Russian twists.