Crunches and sit-ups can be monotonous, and they probably remind you of elementary-school gym class. But they don't have to be boring. There are plenty of variations you can incorporate into your strength-training routine that target the muscles that make up your core.
Standard crunches work your rectus abdominis (front part of your abs), while side crunches recruit more from your obliques and reverse crunches target the hard-to-target lower portion of your abs (technically still part of the rectus abdominis).
Even though doing endless crunches and sit-ups won't get you those six-pack abs you've always wanted, these variations — incorporated into your workout strategically — can be one piece of the puzzle. And by switching up which one(s) you do, you can make sure you're never bored with your ab routine again.
1. Standard Crunch
Let's start with the basics. It's important to perfect proper form of the standard crunch before moving on to any of the other variations.
- Lie on your back with your knees bent and pointed to the ceiling. Bring your hands behind your head so that your elbows flare out to the sides. Your hands can overlap and rest on your head, but they should never pull your neck up during the movement.
- Exhale, contract your abs and lift your head and shoulder blades off the ground. Your neck can curl slightly, but it shouldn't strain toward your chest.
- Inhale as you lower back down so that your head is hovering just off the ground and repeat.
2. Weighted Crunch
- Lie on your back with your knees bent and pointed to the ceiling. Hold a weight at the center of your chest (but not resting on your chest).
- Curl up without letting your chin touch your chest. The weight might move forward (toward your midsection), but make sure that you're holding it above you the entire time so that you feel the full weight.
- Lower back down with control.
Start with a 5-pound medicine ball or dumbbell and work up from there.
3. Reverse Crunch
While you can't technically spot reduce belly fat on your lower abdomen, you can lower your overall body fat, which will reveal your underlying muscle. Pair this exercise with a healthy diet and a good cardio workout schedule
- Start on your back with your hips and knees bent at 90-degree angles. You shins should be parallel to the floor. Place your arms alongside your body with your palms facing down.
- Exhale as you contract your lower abdominal muscles to lift your butt and lower back off the ground.
- Inhale as you release back to the starting position.
Make sure this move is focused on your abs and that you’re not pressing into the ground with your hands.
4. Raised Leg Crunch
- Start on your back with your hips and knees bent at 90-degree angles. You shins should be parallel to the floor. Bring your hands behind your head.
- Holding your legs in place, exhale and crunch up without letting your chin drop into your chest.
- Inhale as you lower back down.
For an added challenge, lift your butt off the ground as your head and shoulders come up — as long as you don’t rely on the momentum of the move to raise and lower.
5. Swiss Ball Crunch
- Lie down, supporting the middle of your back on a Swiss ball so that your head, neck and shoulders are hanging off.
- Contract your abs and raise up off the ball so that you're almost sitting up straight.
- Lower back down slowly. Your upper back can curve down slightly along the edge of the ball as long as this doesn't put strain on your neck or lower back.
Choose a Swiss ball that allows your knees to rest at a 90-degree angle. And be careful not to let you head or neck arch too far backward during the downward movement: Instead focus on letting your back and abs do all the work.
6. Weighted Swiss Ball Crunch
- Hold a medicine ball directly over your chest and lie on a stability ball. Your knees should be at 90 degrees with your middle back supported by the stability ball.
- Contract your abs and raise off the ball, continuing to hold the medicine ball slightly away from your chest.
- Inhale and lower back down so that your head is past parallel with your torso.
Since this variation is advanced, make sure you’ve mastered the stability ball and weighted crunches first before you attempt this one.
7. Frog Crunch
- Start seated with your knees bent out in front of you. Lean back slightly so your torso is at a 45-degree angle to the floor and your shins are parallel to the floor.
- Keep your abs engaged as you straighten your legs and simultaneously bring your arms out to the side.
- Bring your arms and legs back in to the starting position.
- Continue pulsing like this as you hold your core steady.
8. Bicycle Crunch
This crunch variation is popular for a reason — you can challenge your balance and coordination while targeting your mid and lower abs and obliques all at the same time. You might also feel this one in your hips and thighs.
- Start lying flat on your back with your hands behind your head. Contract your lower abs to raise your legs a few inches off the ground.
- Twist your torso and bend your left knee so that your right elbow crosses your body and reaches toward your left knee.
- Now switch and twist to the other side so that your left elbow reaches toward your bent right knee.
- Keep alternating sides without tucking your chin toward your chest.
9. Side Crunch
- Start in the classic crunch position lying on your back with your knees bent. If your lower back is flexible and strong enough, you can drop your knees to one side. If not, stay in the standard starting position, crossing one foot on top of the opposite knee.
- Contract your abs and lift your head and shoulders off the floor, twisting to the side of your bent knees (or just twisting opposite elbow to raised knee).
- Lower back down and complete all reps on one side before switching sides.
Since there are two methods of side crunches, choose the one that doesn’t hurt your lower back.
10. Full Sit-Up
- Start lying on your back with your knees bent and pointed to the ceiling. Bring both hands behind your head without putting undue pressure on your neck.
- Exhale as you lift your entire torso off the ground and toward your knees. Raise from lying down to sitting up in one fluid motion.
- Lower back down with control. Think of your torso as one straight plank from hips to head that raises and lowers like a lever.
Don’t let your chin tuck into your chest, and only use the strength of your abs to pull you up to a seated position. And if you can’t do a full sit-up on your own, have a partner hold down your feet or anchor them under a stable object while you perform all your reps.
11. Wide-Leg Sit-Up
- Begin seated in a butterfly position — knees bent and open toward the floor with your feet together close to your groin.
- Lower yourself down so that your back is flat on the floor and your arms reach overhead.
- Reach up and forward as you pull yourself back up to seated with the strength of your abs.
Even if your hips aren’t super flexible to begin with, you can still get the benefits of this variation and work up to full flexibility over time.
12. Running Man Sit-Up
- Lie flat on the floor with your hands behind your head.
- Exhale as you sit up, twisting your torso and bending your right knee so that you left elbow crosses over your right knee.
- Drop all the way back down to the start before repeating on the other side.
13. Dragon Flag Sit-Up
- Lie on a bench with your arms bent and your elbows by your ears so that you can grip the top of the bench.
- Contract your abs and raise your legs up until your upper body naturally curls with it. If your ab strength allows, keep raising until your feet are over your shoulders.
- Lower your entire body down in a straight plank until you're back to the start. You may need to roll your back out some of the way if you're unable to do the full version.
Though the full version of the dragon flag requires you raise and lower your entire body from shoulders to feet as a single plank, you might need to modify until you build up core strength.
14. Reverse Crunch Pulse
- Begin lying on your back with your legs up in the air, perpendicular to the floor. Keep your arms down along your side with your palms facing down.
- Squeeze your lower abs and raise your butt and lower back off the floor with quick pulses.
- Continue lifting and lowering for the desired number of reps.
You can do this variation either with legs straight up or legs bent at the knees with shins parallel to the floor. Try not to rely on momentum, but focus on only using your lower abs.
- Lie on your back with your arms extended overhead.
- Take a big inhale, and then on your exhale, engage your core and lift both your torso and legs straight off the ground and reach for your toes. You body will resemble a V.
- Lower back down with control, keeping your core tight and your legs straight.
16. Medicine Ball V-Ups
If regular V-ups weren't challenging enough for you, add a medicine ball into the mix and you'll really start to feel your abs fire up.
- Lie on your back, holding a medicine ball with both hands, arms extended over your head.
- On an exhale, lift both your legs and entire torso off the ground as you reach the medicine ball toward your toes.
- Bring the ball back over your head as you lower your back and legs to the ground.
17. Stability Ball Back Crunch
- Face the stability ball, plant you feet on the floor and rest your hips and stomach on the ball.
- Bring your hands behind your head and engage the muscles up and down your back to raise your upper body off the ball.
- Slowly lower back down to the start. Be careful not to strain your neck or lower back as you do this exercise.
18. Russian Twist
- Begin seated and lean back slightly. If your abs are strong enough, lift your feet a few inches off the floor. Either hold your hands in a fist at the center of your chest or extend your arms out in front of you.
- Keeping your core engaged, twist your upper body to the right without lowering your feet or arching your back.
- Hold for a second before twisting back the other way.
- Continue alternating sides without compromising your form.
19. Weighted Russian Twist
- Begin seated and lean back slightly. If your abs are strong enough, lift your feet a few inches off the floor. Hold a medicine ball at the center of your chest.
- Twist from side to side, allowing the medicine ball to add resistance without letting it pull your back out of proper alignment.
The further away from your body you hold the medicine ball during a Russian twist, the greater challenge it will be to your abs and upper body.
20. Scissor-Kick Crunch
- Start lying on your back with your hands underneath your tailbone for support, or simply keep them by your side. Contract your abs and raise your legs a few inches off the ground.
- Keeping your back flat on the ground, raise one leg up toward your chest (or as high as you can while keeping it straight). If your hands are by your sides, you can choose to grab ahold of the raised leg before releasing it back down.
- As one leg lowers, raise the other one.
- Continue to switch off kicking legs.
See how long you can go, keeping your legs perfectly straight and your back flat on the ground.
21. Side Plank Crunch
- Start in a side plank either balancing on your hand or your forearm. Keep your body in one straight line from your feet to your shoulders. Raise your top arm up toward the ceiling.
- Bend your top knee and top arm so that your knee meets your elbow halfway. You should really feel this in your obliques.
- Lower your leg down and return your arm to the start.
- Continue with all reps on one side before switching to the other.