Crunches: 19 Ways to Do a Crunch Exercise To Set Your Core On Fire

If you want to build six-pack abs and a stronger core, consider adding the simple exercise of ‘crunches’ to your ab workouts.

As a core exercise, crunches target your abdominal muscles, specifically working your rectus abdominis (the six-pack muscle) and obliques.

They are an extremely effective bodyweight ab exercise that helps build a stronger core.

When done correctly, crunches target both your upper and lower abdominals.

Another benefit of crunches is that they are gentler on the lower back and carry less risk of injury than traditional sit-ups or the use of an ab machine.

Standard crunches are performed with your feet hip-width apart as you lie face-up.

While keeping your lower back on the floor, lift your upper back and shoulder blades off the floor. With proper form, this abdominal exercise can increase your core strength.

The Benefits of Doing the Crunches Exercise

Before seeking advice on how to perform these ab exercises correctly, you might be wondering why it’s worth your time in the first place.

Below are three fantastic reasons why your abdomen should be blessed with the ab crunch.

More Back-Friendly Than Full Sit-Ups:

Crunches strengthen the rectus abdominis by flexing it. Although you might assume that a sit-up would provide the same benefit, especially since you go higher, the primary ab muscle activates only when you lift your shoulder blades from the ground.

Lifting higher engages the hip flexors, causing excess stress on the lumbar spine. Since the hip flexors are already overworked, they don’t need this additional exercise. With a small range of motion, crunches train your core without straining your back.

Build Muscular Endurance

Abdominal muscles play a crucial role in stabilizing your midsection, allowing you to maintain good posture, lift heavy objects, and perform twisting and rotating movements.

Given that these are daily activities, your abs must be able to sustain long periods of work. Abdominal crunches help build this essential muscular endurance, requiring muscle fibers to endure resistance for an extended period.

In a study, one day of crunches a week improved abdominal endurance in a group of people who had never trained their abs.

More Effective Than Using Ab Gadgets

While infomercials promise that gadgets can flatten and define your abs, the most effective method is often overlooked. To measure effectiveness, the American Council of Exercise conducted a small study comparing various gadgets (Ab Crunch machine, Ab Circle Pro, ab roller, Ab Lounge, ab rocket) against the traditional crunch.

The study found that the traditional crunch was more effective at activating major abdominal muscles. Moreover, unlike gadgets, crunches don’t require additional spending or storage space. You can perform this exercise almost anywhere with some floor space and a bit of motivation. It’s a great addition to your ab workouts for building a strong core.

The Basic Crunch

Before we delve into the various ways you can perform crunches, let’s start by covering the basics. We’ll walk you through how to do a standard crunch, and then we’ll introduce you to a range of effective variations that will keep challenging your core. Feel free to choose a few of these variations to add to your regular ab routine

How to Do a Basic Crunch Correctly

“The perfect fitness crunch can only be done through the safe and accurate practice of the procedure.

Maintain good form throughout each set and repetition. Aim for two to three sets of 10 to 15 repetitions for crunches.

Once your form breaks, stop the exercise to avoid injury.

A yoga mat is essential for every crunch fitness workout to get easier on your back and stay clean.

Now, here’s a step-by-step guide on how to perform a basic crunch:

1. Lie down on your back with your face up on an exercise mat, with your knees bent and your feet flat on the ground.
2. Hold both hands behind your head without interlocking them. Make sure that your spine and pelvis are in a neutral position.
3. Engage your core as you tuck your pelvis slightly and lower your ribcage. As if holding an egg underneath your chin, keep your chin tucked throughout the movement. Start all repetitions from this position.
4. Squeeze your abs as you move upward. While squeezing your abs, lift your shoulders off the floor. When you reach the top, pause.
5. Lower your shoulders slowly to the floor while keeping your abs tight. Do the exercise until you reach the desired number of repetitions.

Now that you know how to do crunches with proper form, here are 19 different ways you can do a crunch.

18 Ab Crunch Exercises to Build a Stronger Core

Each crunch exercise featured in this listicle offers unique benefits, targeting various muscle groups and contributing to a well-rounded core workout.

1. Bicycle Crunch

Fitness enthusiasts have loved this movement for years, and with good reason. Bicycle crunch was ranked the best for strengthening your rectus abdominis and obliques.

• Lie face-up with your lower back pressed to the mat. Contract your ab muscles by pulling your navel in towards your spine. Place your palms behind your head, but don’t lace your fingers.
• Bring your knees in towards your chest and lift your shoulder blades off the mat. Be sure not to pull your neck or head.
• In one motion, straighten your right leg out while turning your upper body to the left. Bring your right elbow towards the left knee. Make sure your rib cage is moving, not just your shoulders and arms.
• 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.

2. Scissors (Straight Leg Variation)

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

The scissor kick exercise engages your core muscles, glutes, quadriceps, and adductors.

Your core muscles are what allow you to “flutter” your legs up and down.

There are four core muscles: the rectus abdominis, the obliques, the transverse abdominis, and the hip flexors.

• 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.
• 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.

3. Cross Sit-Up

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

• Lie face-up in a neutral position with your arms out to the sides, making a T with your body.
• Contract your abdominals. 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.

4. Crunch Clap

The crunch clap demands more physical activity because of the extra steps – claps.

Because of this, they’re a great exercise for more movement, calorie burn, and bolstering core strength.

• 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.
• Lower your leg and repeat on the other side. Continue alternating for 12 repetitions per side.

5. Side V-Crunch

This core exercise is great for targeting and working the oblique muscles. 

If you’re trying to get rid of the love handles or muffin top, this workout is great to add to the love handle workout.

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

6. Reverse Crunch

The reverse Crunches are great for hitting the lower abs, internal and external obliques.

• 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.
• 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.”

This maintains a consistent past tense for the entire set of instructions.

7. Vertical Crunches (Vertical Leg Crunches)

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

8. Crunch Frogs

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

• 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.
• Pull your knees in, while at the same time wrapping your arms around your legs.
• Contract your abs, then extend your legs as you open your arms to your sides. Repeat for 12-15 repetitions.

9. Runner’s Crunch

• Lie face-up with your arms bent at 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.
• Crunch up and swing one arm. Mimic the running motion and bring the opposite knee up.
• Slowly reverse the motion and repeat with the opposite leg and arm. Complete 12-15 times per side.

10. Bird Dog Crunch

• 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.
• Keep your back stable, and straighten your right arm and left leg. Alternate sides and do ten bird dogs per side.

11. Diamond Sit-Up

• Lie face-up and butterfly your legs into a diamond shape with the soles of your feet pressed together on the floor. Keep your knees split wide apart. Extend your arms over your head.
• 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.

12. V-Sit Ups

The V-sit-up is an effective ab workout. It targets your rectus abdominis, external obliques, and internal obliques. It also works the hip flexors while improving core strength.

• Lie face-up with your arms by your side. Lift your legs and torso off the floor to start.
• Bring your knees in and bring up your torso higher with your 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 12-15 times.

13. Oblique Crunch

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

• Lie on with your left side down with your right hand behind your head. Keep your left hand on the floor for support.
• 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.

14. Mountain Climbers

Mountain Climbers are one of the few cardio exercises on this list. They target your core and will increase the number of calories you burn simultaneously.

• Start in the same position you would do pushups. Keep your hands shoulder-width apart and legs fully extended behind you. Be sure to keep your weight on your toes.
• Bring your right foot forward by bending the right knee and putting the weight on the ball of your left foot.
• 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. As you get the hang of them, increase your speed to add intensity to this workout.

15. Side Plank Crunch

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

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

16. 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.

• Lie face-up with your legs in a tabletop position. Contract your abdominal muscles to round your lower spine.
• 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.
• Keeping your shoulders off the floor, pump your right and left arm up and down with a small range of motion. While keeping your arms straight, inhale for five arm pumps and exhale for five pumps.

17. Swiss Ball Crunches

Physical therapists love stability balls. They’re great for improving core strength, mobility, and flexibility.

They are also highly ranked for engaging your rectus abdominis in this exercise.

• 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.
• Your lower back should feel like it’s curved around the ball. Gently place your hands behind your ears and draw in your abs.
• 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.

18. Dragon Flag Sit-Up

The DragonFly SitUp is best with a bench if outdoor. At home, you can also do this one on the floor with something you can hold to support your weight.

• Lie on a bench with your arms bent and elbows by your ears so that you can grip the top of the bench.
• Contract your abs and raise your legs until your upper body naturally curls with it.
• 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.

Crunches Workouts to Strengthen Your Abs

Here’s a quick crunch workout routine you can do at home to strengthen your abdominal muscles.

Workout 1:

• Basic/standard crunch: 10 X 3, 10 Secs Rest
• Oblique Crunch: 10 X 3, 10 Secs Rest
• Runner’s Crunch:10 X 3, 10 Secs Rest

Workout 2:

• Basic/standard crunch: 10 X 3, 10 Secs Rest
• Side Plank Crunch: 10 X 3, 10 Secs Rest
• Bird Dog Crunch:10 X 3, 10 Secs Rest
• Runner’s Crunch:10 X 3, 10 Secs Rest

To increase the intensity of the crunch workout challenge, try adding free weights.

Crunches Questions and Answers

These crunch variations are great for strengthening your core and abs. With that said, crunches alone are not enough to flatten your abs. It’s also essential to pair it with a healthy and balanced diet.

Not sure what to eat to lose belly fat? Start with our easy, simple 7-day healthy meal plan to lose belly fat.

By combining your diet and workouts, you can develop a defined six-pack.

Are Crunches Effective?

Regular crunches (and variations) are effective in isolating and targeting the rectus abdominis. They’re also helpful in building six-pack abs.

But doing crunches alone won’t help you lose stomach fat and get a flat belly. It would help if you combined crunches with other core exercises to build a strong core.

To strengthen the entire muscle groups in the trunk, you need other variations of an ab crunch.

You also need varying planes of movement, angles, and positions in your workout.

How Many Crunches Should I Do a Day?

10-12 reps and 3 sets of crunches will be good enough.

In addition, you may do three sets of two or three variations to engage the other muscles in the stomach.

How To Stay Safe and Avoid Injury When Performing Crunches

Always remember to follow physical activity guidelines and posture protocol.

If not done in a controlled fashion with good form, the traditional crunch can do more harm than good.

You can strain your back and neck from spinal flexion (bending forward).

If you feel any sharp pain in the back, stop the exercise immediately.

Who Should Avoid Crunches

Generally, the ab crunch can also be unsafe for older adults with weak backs. Avoid this exercise if you have poor stability and lack good core strength.

Final Takeaway In Doing Crunches

Crunches are an easy exercise you can do at home to strengthen your abdominal muscles. Though it helps you strengthen your six-pack abs, it isn’t enough to reduce your belly fat.

It also only targets the abdominal muscles by isolating them. It does not provide any functional core workout like planks.

If your goal is to build core strength, incorporate alternative exercises such as the bird dog, mountain climber, and plank.

These moves not only engage core muscles but also reduce back stress.

If you have back pain, crunches may not be the best ab exercise for you. As it could worsen your pain.

A personal trainer (or another qualified third party) can help you recommend modifications and alternatives to give you the best core workout.