Crunches: 19 Ways to Do an Ab Crunch Exercise

Crunches used to be one of the most popular workouts for abdominals; however, in the last few years, they have become less popular.

And that’s too bad because they are easy to do bodyweight exercises, with plenty of modifications to suit anyone’s fitness level. The problem might be that people were trying to crunch their way to ripped abs, and that just isn’t how things work. What you want is a variety of movements that will build core strength throughout your entire midsection.

The regular crunch is still one of the best ab exercises for targeting the rectus abdominis muscle, (otherwise known as your six-pack muscles.) The modifications and variations below will also hit your hip flexors, oblique muscles including outer and internal obliques, your transverse abdominis, your glutes, and more.

So, a great way to build a strong core is to put together an exercise program combining these moves. Even if you aren’t concerned about belly fat or a tight abdomen, there are great reasons to do ab work. Core stability helps reduce the risk of injury, can relieve back and neck pain, and can improve your posture.

These moves improve spinal flexion, which your doctor’s way of saying “bending forward.” Flexion is the movement you do in deadlifts, or picking up a child, or gardening. By strengthening the muscle groups used in spinal flexion, you can help prevent or help relieve lower back pain.

Want more? At the bottom of the page, we’ll link to additional resources and posts from the Fitwirr web site for improving your abdominals.

Below we will cover the basic crunch and other workouts that will engage your rectus abdominis and help you develop a six-pack. We’ll also go through different modifications that you can add to your exercise routine to build your core muscles and hit your fitness goals.

However, if you have belly fat, it’s also essential that you clean up your diet and watch the number of calories you consume. If there is a layer of fat sitting on top of your muscles, you may have a strong core, but still not have muscle definition. If that is your goal, you need a good diet, a mix of endurance or cardio exercise, strength training, and a great ab workout. 

Are Crunches Effective?

Is crunch fitness a thing? Yes. But a basic crunch is not the most effective exercise. A study sponsored by the America Council on Exercise compared 13 of the top-ranking, common abdominal exercises and their muscle activation level (1) It found that other variations, some using a stability ball, were a more effective way to work this muscle group. But, to get to the powerful and most effective ab workouts, we are going to walk you through a regular crunch first. 

Any trainer will tell you that for educational purposes and correct form, you should start at the beginning. Once you understand the basic crunch, we will move to the best workouts for your obliques, rectus abdominis, spinal flexion, and more! Consider this article your own session with a personal trainer. 

1. Basic Crunch: How to Do Crunches

Step by step directions on how to do a basic crunch with proper form:

Now that you understand the crunch position let’s look at other variations.

All of these will build core strength and improve flexion of your spine. Remember that study we mentioned by the America Council on Exercise? They ranked the next one as the top ab workout for your rectus abdominis.

2. Bicycle Crunch

Fitness enthusiasts have loved this movement for years, and with good reason. This movement was ranked the best for strengthening your rectus abdominus.

1. Lie faceup with your lower back pressed to the mat. Contract your ab muscles by pulling your navel in towards your spine. Place your hands behind your head, but don’t lace your fingers.
2. Bring your knees in towards your chest and lift your shoulder blades off the mat. Be sure not to pull your neck or head.
3. In one motion, straighten your right leg out while turning your upper body to the left, bringing your right elbow towards the left knee. Make sure your rib cage is moving, not just your shoulders and arms.
4. Go through a bicycle pedal motion, slowly at first. Do 12 repetitions per side.

If you are these, you are speeding through these; you are doing them the wrong way. Take a deep breath and slow down. This type of exercise will be more effective if you move deliberately and under control.

3. Scissors (Straight Leg Variation)

Do you want to increase the difficulty of the bicycle crunch? Use the same motion, but keep your legs straight.

1. Lie face-up and brace your core muscles, bringing your navel to your spine. Use your abs to lift your upper body off the floor.
2. Lift both legs off the floor. Now, lower your left leg and twist your body to the right. Scissor your legs, turning towards the upraised leg. Complete 10-12 repetitions per side.

4. Cross Sit-Up

Let’s up the intensity of this ab workout one more time. In this variation, keep your arms and legs straight.

1. Lie face-up in a neutral position with your arms out to the sides, making a T with your body.
2. Contract your abdominals, and lift your right leg while twisting to bring the fingertips of your left hand to your right toes. Return with control and repeat on the other side. Do 12 repetitions on each side.

5. Crunch Clap

1. Lie face-up with your knees bent. Brace your core muscles and curl your shoulders towards your pelvis as you rise. Bring one leg up and clap your hands underneath the raised leg.
2. Lower your leg and repeat on the other side. Continue alternating for 12 repetitions per side.

6. Side V-Crunch

1. Lie down on your right side with your right hand on the ground for support. Place your left fingers gently behind your left ear.
2. In one motion, lift your left leg off the ground and raising your left shoulder and upper body towards your leg to create a V shape.
3. Pause then return. Repeat ten times and switch sides.

7. Reverse Crunch

Reverse Crunch exercises are great for hitting your internal and external obliques.

1. Lie face-up with your hands on the floor. Contract your abs while lifting both legs up with your knees bent. Keep your low back on the floor.
2. Use your lower abs to slowly curl the hips off the mat and into your chest. Slowly return to the starting position and repeat 12 times.

8. Vertical Crunches

1. Lie face-up with your legs extended in the air. Keep your hands behind your head.
2. Contract your abdominal muscles by lifting your upper body toward your knees. Pause at the top and return to the starting position. Repeat 12 times

9. Crunch Frogs

Crunchy frogs are an exercise for abs specifically created by P90X personal trainer, Tony Horton.

1. Start by sitting in a V-like position with your arms extended out. Lift your feet up and recline your torso slightly to balance on your tailbone, so your body is at a 45-degree angle.
2. Pull your knees in, while at the same time wrapping your arms around your legs.
3. Contract your abs, then extend your legs as you open your arms to your sides. Repeat for 12-15 repetitions.

10. Runner’s Crunch

1. Lie face-up with your arms bent a 90-degree angle, so the back of your arms are on the floor, and your hands are in the air. Extend your legs straight out in front of you.
2. Crunch up and swing one arm. Mimic the running motion and bring the opposite knee up.
3. Slowly reverse the motion and repeat with the opposite leg and arm. Complete 12-15 times per side.

11. Bird Dog Crunch 

1. Get on all fours in a tabletop position. Contract your ab muscles to start. Slowly bring your left knee and right elbow together under your midsection.
2. Keeping your back stable, straighten your right arm and left leg. Alternate sides and do ten bird dogs per side.

12. Diamond Sit-Up

1. Lie face-up and butterfly your legs into a diamond shape with the soles of your feet pressed together on the floor, and your knees split wide apart. Extend your arms over your head.
2. In one motion, curl up your torso and tap the floor in front of your feet. Slowly return to the starting position. That’s one rep. Continue for 12-15 repetitions.

13. V-Sit Ups

1. Lie face-up with your arms by your side. Lift your legs and torso off the floor to start.
2. Bring your knees in and bring up your torso higher with arms out right in front of you. Slowly return your upper body to the floor and straighten out your legs as you do. Stop when your back is on the floor, but not your head, shoulders, or legs. Repeat for 12-15 times.

14. Oblique Side Crunch

Oblique side crunches are great for your obliques, those side muscles responsible for lateral flexion and rotation.

1. Lie on with your left side down with your right hand behind your head. Keep your left hand on the floor for support.
2. Press down into your left hand as you raise your legs off the floor, bringing your torso towards your legs. Return to the start with control. This completes one repetition—aim 10-12 reps per side.

15. Mountain Climbers

Mountain Climbers are one of few aerobic exercises on this list. They work your core and will increase the number of calories you burn at the same time.

1. Start in the same position you would do pushups, with your hands shoulder-width apart and legs fully extended behind you. Be sure to keep your weight on your toes.
2. Bring your right foot forward by bending the right knee and putting the weight on the ball of your left foot.
3. Switch legs, bringing the left knee forward while moving the right leg back—aim 12-15 reps per side.

Start your mountain climbers slow and under control, but as you get the hang of them, increase your speed to add intensity to this workout. 

16. Side Plank Crunch

This plank variation is also great for strengthening your shoulders and upper back.

1. Start in a side plank position with your left elbow down, and your right arm extended, hand in the air towards the ceiling.
2. Keeping your torso stable and your waist lifted, bring your right leg up and your right arm down and lightly tap your right elbow with your right knee. Try not to lean forward or backward.
3. Return your right leg to the starting position and repeat. Continue for 12-15 repetitions before switching to the other side.

17. Pilates 100s

These look simple, but they can be tough! Beginners should start with 10 – 15 reps, and then you can work your way up.

1. Lie face-up with your legs in a tabletop position. Contract your abdominal muscles to round your lower spine.
2. Exhale and lift your upper back off the floor until the bottom tips of your shoulder blades skim the floor. Straighten your legs and reach your arms toward your feet into a hollow hold.
3. Keeping your shoulders off the floor, pump your arms up and down with a small range of motion while keeping your arms straight. Inhale for five arm pumps and exhale for five pumps. 

18. Swiss Ball Crunches

Physical therapists love stability balls. Also called exercise balls, these balls are an inexpensive piece of fitness equipment that can help you improve mobility and flexibility. They are also highly ranked for improving flexion and working your rectus abdominis in this exercise.

1. Sit on an exercise ball with your feet flat on the floor. Walk your feet forward, so half of your back is on the ball. Stop when the ball is under your hips, lower back, and middle back. Be sure that your thighs remain parallel to the floor.
2. Your lower back should feel like it’s curved around the ball. Gently place your hands behind your ears and draw in your abs.
3. Raise your chest up and slightly forward in a crunching motion. Do not pull from the neck, and don’t let your head drop. You reach the end of your range of motion when the middle of your back loses contact with the Swiss ball.

19. Dragon Flag Sit-Up

The DragonFly Sit-Up is best with a bench, but you can also do this one on the floor if you have something you can hold to support your weight. 

1. Lie on a bench with your arms bent and elbows by your ears so that you can grip the top of a bench.
2. Contract your abs and raise your legs until your upper body naturally curls with it.
3. If your ab strength allows, keep coming up until your feet are over your shoulders. Then lower your entire body down with control. Repeat 12 – 15 reps.

Final Thoughts

There you have it! Nineteen ab building workouts you can mix and match to build a fantastic workout. If you are new to exercise, you may want to seek medical advice on how often you should work out.

Or, if this is your first time, having a fitness instructor walk you through these exercises might be beneficial. They can ensure you have proper form. But you don’t have to spend hours on these movements. Select a few and add five or ten minutes to your regular exercise routine.

You can use them as a warm-up before heavy squats, for example, or as a cool down after a run. None of these require much in the way of equipment, outside of a mat and an exercise ball, so they are excellent for doing at home. Remember that all of these should be done slowly and under control.

The mountain climber is only one that can be done fast, and even then, you want to maintain balance and good form.

If you enjoyed this article, here is some similar content on the Fitwirr web site to check out:

• 11 Best Ab Workouts for Men
• 25 Best Ab Exercises for Women
• How to Lose Belly Fat Fast: 7 Effective Tips Based on Science