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Crunch

The importance of core training can frequently be overlooked. Whether you’re an average gym-goer or an experienced athlete, incorporating core exercises like the crunch should be prioritized. The reason is that core strength can directly impact the quality of your exercise performance. 

The crunch boasts numerous desirable benefits for improving posture and reducing injury risk. In this guide, we’ll show you how to do the crunch and how to add it to your workout routine. From there, you can reap the benefits of this effective core exercise in strengthening muscles and improving posture.

How To Do

  1. Place a mat or towel down on a flat surface.
  2. Lie down with your legs straight and arms at your sides. 
  3. Cup the back of the head with elbows flared out at approximately 90 degrees. 
  4. Draw the knees up so your feet are flat on the floor.
  5. Engage the core, using it to lift the shoulders off the ground and crunch to the knees. 
  6. Pause at the top of the movement. 
  7. Slowly return to the starting position.
  8. Repeat for the desired reps and sets.

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Tips From Expert

  • A common mistake people make when performing the crunch is using the shoulders and neck rather than the core muscles. Prioritize mind-to-muscle connection to ensure the abdominal muscles are engaged throughout the exercise. 
  • Control the exercise's movement. It’s easy to use momentum to avoid muscle engagement, but this defeats the exercise's purpose. Slow down the lowering portion of the movement to prevent momentum use and promote better muscle engagement.

Optimal Sets and Reps

Before you begin performing crunches, it’s essential to determine your fitness goals. Once you do, you can pinpoint the ideal sets and reps to progress in your fitness journey.

Training TypeSetsReps
Strength Training3–53–5 (weighted)
Hypertrophy3–48–12
Endurance Training3–412–20
Power Training3–53–5 (weighted)
Optimal Sets & Reps of Crunch

How to Put in Your Workout Split

The crunch is one of the most commonly known abdominal exercises in the fitness space. Many hardcore gym enthusiasts and average gym goers have used this exercise to strengthen their core muscles

In exercise, especially free-weight exercises, the core muscles are active to support balance and stability to reduce injury risk. Some examples of free-weight core exercises include planks and V-sits. 

Core exercises can typically be inserted into any workout day in the different workout splits, like upper and lower body days. Crunches can be added to the end of the workout before cooling down post-workout to limit fatigue before training. Determine in your split which days you want to incorporate core exercises like crunches to improve abdominal strength. 

If your goal is to increase abdominal strength or endurance, follow the recommended sets and repetitions in your training program. In endurance training, exercises need to be performed with higher repetitions. This helps muscular endurance by increasing the time your muscles contract under force. 

For strength goals, exercises must be performed with lower repetitions and higher intensity. For advanced-level lifters, not beginners, to increase the intensity of bodyweight exercises like crunches, add weight. Grab weighted equipment like a kettlebell or dumbbell to increase intensity and encourage strength and power gains.

For power and strength-focused goals, advanced lifters can add weight to increase the intensity to perform at lower rep ranges. This will also make the bodyweight exercise more challenging for advanced lifters. Beginner lifters should keep the exercise bodyweight until they build up strength and proper form.

Primary Muscle Groups

Upper Rectus Abdominis

Muscles located just below the lower chest and above the lower abdominals. Between your ribs and pubic bone.

Upper Rectus Abdominis 

The upper rectus abdominis is a muscle that runs vertically from the pubic bone to the upper abdomen. The primary function of this abdominal muscle is to move the spinal column and flex the trunk. 

The upper rectus abdominis plays an important role in core stability. It adjusts pelvic tilt, tenses the anterior wall of the abdomen, and protects the lower back from injury. 

Keeping this muscle strong is vital for deterring respiratory and other posture-related disorders, like ptosis. Abdominal ptosis, or visceroptosis, is a condition where the abdominal organs drop from their normal position in the body. This medical issue is linked to weak muscles that can’t support the body’s internal organs.   

In the crunch, the upper and lower rectus abdominis are actively engaged to promote movement in the spine. Incorporating exercises like the crunch into your training can strengthen these abdominal muscles to decrease injury risk and support posture. Use other upper ab workouts to target muscles like the upper rectus abdominis. 

*Expert Tip: To increase the intensity of the crunch, don’t relax on the floor at the bottom of the movement. Keep the shoulders from touching the mat to maintain tension in the abdominal muscles for a challenge.  

Secondary Muscle Groups

Lower Rectus Abdominis

Muscles located below your upper abs and above your public bone between your ribs.

Obliques

Muscles located on the sides of your rectus abdominals. Runs on the sides of your trunk.

Erector Spinae

Muscles that span the entire length of your spine on either side.

Lower Rectus Abdominis 

The lower rectus abdominis is part of the rectus abdominis muscle of the abdomen. It makes up the lower section beneath the transversus abdominis, another abdominal muscle. Like its upper counterpart, the lower rectus abdominis stabilizes the body and flexes the spine. 

This muscle is necessary for various functions, like compressing the abdomen and keeping internal organs in place. When we cough, sneeze, and lift heavy loads, abdominal muscles like the lower rectus abdominis contract to stabilize the spine. It supports trunk-focused actions, like rotation and extension, when we turn and bend over to pick something up. 

The crunch exercise engages the lower rectus abdominis, which supports the trunk extension needed to perform the movement. Engaging this muscle with exercises like the crunch can strengthen it, stabilize the spine, and reduce injury risk. Consider using deep core exercises to target muscles like the transversus abdominis. 

Obliques

The obliques are a pair of abdominal muscles divided into internal and external obliques. These muscles travel along the sides of the abdomen, over the ribcage, and by the rectus abdominis. 

The external obliques are the largest and closest to the surface. The internal obliques are thinner and located beneath the external obliques. Both are important for supporting the trunk's rotational and side-to-side movement needed for turning and bending. 

The obliques are incorporated into the crunch exercise to stabilize the spine during the movement. Though there aren’t any side-to-side movements in this exercise, the torso is bending. This activates the use of the obliques to support trunk movement, which increases muscle strength and spine stability. 

Erector Spinae

The erector spinae, or spinal erectors, are a group of large, superficial muscles. These muscles travel from the neck to the lower back, supporting lateral flexion and extension of the neck and spine. Bending to the side to pick something up uses the erector spinae to support this motion. 

Maintaining health and functionality in the erector spinae is crucial for supporting everyday activities. This muscle is necessary for activating and correcting movement in the spine, which is crucial for preventing poor posture. Poor posture can cause spinal issues, back pain, and discomfort, affecting quality of life. 

The erector spinae are activated in the crunch exercise to establish the spinal movement needed to crunch or bend upward.

Equipment

Bodyweight

Bodyweight

Requires bodyweight resistance and additional equipment for proper execution.

Variations

Exercises that target the same primary muscle groups and require the same equipment.

Alternatives

Exercises that target the same primary muscle groups and require the different equipment.

Who Should Do?

Lifters And Athletes

Lifters and athletes can benefit from incorporating crunches into their workout routines. A strong core stabilizes and protects the spine during movement and when bearing heavy loads. 

Good core strength can reduce injury rates in athletes and lifters. Preventing injury is crucial for athletes to avoid downtime to recover and stop it from affecting athletic performance. The same can be said for lifters who want to remain injury-free and hit their fitness goals. 

All athletes and lifters should prioritize core training, including exercises like crunches, to increase core strength. This is an effective preventative measure that can help lifters and athletes prevent injury and boost core functionality in exercise performance. 

Beginners

Crunches are a beginner-friendly exercise for first-time gym goers and experienced fitness enthusiasts. Anyone wishing to improve core strength can use this popular core exercise for athletic or functional purposes. They’re easy to perform and progress.

Crunches can benefit beginners by helping build foundational core strength. As a beginner lifter, this is vital for protecting the spine and supporting proper form in exercise. No matter the fitness level, prioritizing core strength can enhance exercise performance to help them reach their goals. 

*Expert tip: As a beginner, start small on the crunches and work your way up. Ensure you maintain the proper form before increasing the repetitions.

Home Gym Exercisers

Not all exercises require equipment. This is a big benefit of bodyweight exercises like crunches. This core-focused exercise requires no equipment, so home gym exercisers can seamlessly incorporate it into their training routine. 

Crunches can be performed in your bedroom, hotel room, or garage gym. They require little space and zero equipment, another benefit for individuals with limited space.

Who Should Not Do?

Anyone With An Injury

Anyone with an injury to the back, abdomen, or neck should not perform crunches. The exercise can make existing injuries worse, resulting in pain or further injury.  People with forward head posture or who have back problems may find that this exercise is uncomfortable. 

Some crunch alternatives for these individuals would be planks and mountain climbers. The position for these exercises reduces tension placed on the neck and back. For individuals with abdomen injuries, please consult with your doctor before performing. 

Older Populations With Mobility Issues

Older populations with mobility issues may find difficulty performing the crunch exercise. As the crunch is performed on the ground, these individuals may have difficulty getting up and off the floor. This exercise may also be hard on the back, especially if they have tight muscles or limited mobility. 

In this case, a detailed consultation is needed with a qualified healthcare professional. They assess your ability to exercise and perform the movement.

Benefits Of The Crunch

Core Strengthening 

Crunches are one of the most well-known abdominal exercises for improving core strength. They engage various muscles, such as the upper and lower rectus abdominis, which are important for supporting daily functions. 

Core strength is connected to core stability needed by the general population, athletes, seniors, and people with disabilities. Balance loss is attributed to aging and disabilities like autism, which can raise the risk of injury. Emphasizing core strength is essential to maintaining balance and posture control and reducing injury risks. 

Incorporate exercises like crunches into your training routine to support balance and stability and protect the spine from injury.  

Flexibility And Mobility

Another important aspect of incorporating crunches is that they can improve flexibility and mobility. These are directly impacted by core strength, which also affects stability in movement. Incorporating crunches into your routine can stretch tight muscles in the hips and lower back. 

Performing resistance training exercises has many positive effects, like increasing flexibility. This exercise can strengthen the muscles in the core to promote better flexibility and mobility in the spine and hips. Movement patterns, like bending at the tips to pick something up, can be made easier and less tight. Spoting movements, like playing basketball, can also be improved.

Improved Posture

In today’s society, a large population suffers from neck and back pain due to poor posture. One reason for this is that individuals adopt poor posture in their school or work environments. A big factor contributing to this is that muscles are not strong enough to maintain proper posture. 

In a study looking at poor posture from gadget use and lower back pain, 70.5% of responders reported musculoskeletal pain.

Fixing poor posture and strengthening muscles that support posture can reduce related symptoms like back and neck pain. Crunches are a beneficial exercise that can strengthen the abdominal muscles to support trunk and spinal stability. Stabilizing the spine and pelvis can promote better posture in daily life. 

Zero Gym Equipment 

Another excellent quality of crunches is that they require zero gym equipment. As a bodyweight exercise, crunches can be performed anywhere, even with limited space. 

Whether you have a home gym or are constantly traveling, crunches can be implemented into your training routine. Other bodyweight ab exercises can be used as well to improve core strength in the comfort of your home gym. 

Frequently Asked Questions

Do crunches burn belly fat?

Spot reduction through exercise is not practically possible. Research has continuously debated the myth of reducing fat in specific areas with exercise. To encourage fat reduction, we advise implementing a caloric deficit with balanced nutrition and exercise.

Are crunches a good exercise?

Yes, crunches are a good and popular exercise for all fitness levels. They can increase abdominal strength and support healthy posture. This exercise can easily be performed at home, a hotel, a gym, or anywhere.

How many crunches per day?

Crunches don’t need to be performed daily as the muscles need time to recover and strengthen from exercise. How many crunches you perform when you train depends on your fitness goals. Allow at least 48–72 hours between sessions.

Resources

Endomondo.com refrains from utilizing tertiary references. We uphold stringent sourcing criteria and depend on peer-reviewed studies and academic research conducted by medical associations and institutions. For more detailed insights, you can explore further by reading our editorial process.

  1. Calatayud, J., Vinstrup, J., Markus Due Jakobsen, Sundstrup, E., Brandt, M., Jay, K., Juan Carlos Colado and Lars Louis Andersen (2015). Importance of mind-muscle connection during progressive resistance training. European Journal of Applied Physiology, [online] 116(3), pp.527–533. doi:https://doi.org/10.1007/s00421-015-3305-7.
  2. Schoenfeld, B.J., Grgic, J., Van, D.W. and Plotkin, D.L. (2021). Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum. Sports, [online] 9(2), pp.32–32. doi:https://doi.org/10.3390/sports9020032.
  3. Fabricio H.O. Silva, Arantes, F.J., Gregorio, F.C., Fhillipe R.A. Santos, Fidale, T.M., Bérzin, F., Bigaton, D.R. and Lizardo, F.B. (2020). Comparison of the Electromyographic Activity of the Trunk and Rectus Femoris Muscles During Traditional Crunch and Exercise Using the 5-Minute Shaper Device. Journal of strength and conditioning research, [online] 34(1), pp.1–10. doi:https://doi.org/10.1519/jsc.0000000000003250.
  4. Sevensma, K.E., Leavitt, L. and Pihl, K.D. (2023). Anatomy, Abdomen and Pelvis, Rectus Sheath. [online] Nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK537153/#:~:text=Contraction%20of%20the%20rectus%20abdominis%20and%20pyramidalis%20muscles%20causes%20flexion%20of%20the%20lumbar%20spine.%20Abdominal%20wall%20muscles%20also%20play%20a%20significant%20role%20in%20intra%2Dabdominal%C2%A0pressure%C2%A0and%20provide%20support%20to%20the%20axial%20skeleton.
  5. Thiago Montes Fidale, Farnesi, F., Roever, L., da, G., Alexandre Gonçalves, Eduardo Paul Chacur, Pimenta, C., Eduardo Gasparetto Haddad, Guilherme, Fábio Clemente Gregório, Cardoso, F., Franciel José Arantes, Santos, Adriano Alves Pereira, Karen, H., Guilherme Morais Puga and Frederico Balbino Lizardo (2018). Eletromyography of abdominal muscles in different physical exercises. Medicine, [online] 97(17), pp.e0395–e0395. doi:https://doi.org/10.1097/md.0000000000010395.
  6. Gomirato, A.P. and Grenier, S.G. (2023). Diagnostic Ultrasound Shows Preferential Activation of Rectus Abdominis Segments with Exercises Targeting Upper Versus Lower Segments. International journal of exercise science, [online] 16(1), pp.1077–1086. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10824285/#:~:text=Rectus%20abdominis%20shortening%20and%20thickening%20was%20observed%20in%20all%20the%20exercises%20tested%20but%20was%20most%20pronounced%20in%20the%20abdominal%20crunch.
  7. Flynn, W. and Vickerton, P. (2023). Anatomy, Abdomen and Pelvis: Abdominal Wall. [online] Nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK551649/#:~:text=The%20abdominal%20muscles%20contribute,to%20cause%20active%20expiration.
  8. Fan, C., Fede, C., Gaudreault, N. and Stecco, C. (2018). Anatomical and functional relationships between the external abdominal oblique muscle and the posterior… [online] ResearchGate. Available at: https://www.researchgate.net/publication/327056634_Anatomical_and_functional_relationships_between_the_external_abdominal_oblique_muscle_and_the_posterior_layer_of_the_thoracolumbar_fascia.
  9. Oliva-Lozano, J.M. and Muyor, J.M. (2020). Core Muscle Activity during Physical Fitness Exercises: A Systematic Review. International journal of environmental research and public health/International journal of environmental research and public health, [online] 17(12), pp.4306–4306. doi:https://doi.org/10.3390/ijerph17124306.
  10. Polat, M., Demirsoy, N. and Tokgöz, N. (2022). Association between abdominal muscle activity and lumbar muscle morphology, and their role in the functional assessment of patients with low back pain: A cross-sectional study. Journal of musculoskeletal & neuronal interactions, [online] 22(3), pp.375–384. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9438515/.
  11. Modes, R.J. and Sevda Lafci Fahrioglu (2023). Anatomy, Back. [online] Nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK539746/.
  12. Matheve, T., Hodges, P. and Lieven Danneels (2023). The Role of Back Muscle Dysfunctions in Chronic Low Back Pain: State-of-the-Art and Clinical Implications. Journal of clinical medicine, [online] 12(17), pp.5510–5510. doi:https://doi.org/10.3390/jcm12175510.
  13. Blasimann, A., Eberle, S. and Scuderi, M. (2018). Effekt eines Rumpfkräftigungsprogramms (inklusive Unterarm- und seitlichem Unterarmstütz) auf die Verletzungsrate von erwachsenen Fußballspielern: eine systematische Literaturübersicht. Sportverletzung, Sportschaden, [online] 32(01), pp.35–46. doi:https://doi.org/10.1055/a-0575-2324.
  14. Lupowitz, L.G. (2023). Comprehensive Approach to Core Training in Sports Physical Therapy: Optimizing Performance and Minimizing Injuries. International journal of sports physical therapy, [online] 18(4). doi:https://doi.org/10.26603/001c.84525.
  15. Jha, P., Nuhmani, S., Kapoor, G., Al Muslem, W.H., Joseph, R., Kachanathu, S.J. and Alsaadi, S.M. (2022). Efficacy of core stability training on upper extremity performance in collegiate athletes. Journal of musculoskeletal & neuronal interactions, [online] 22(4), pp.498–503. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9716297/#:~:text=After%20five%20weeks%20of%20core%20stabilisation%20training%20program%2C%20the%20measures%20of%20UQ%2DYBT%20and%20FTPI%20were%20improved%2C%20thus%20advocating%20the%20use%20of%20a%20core%20stabilisation%20training%20program%20among%20collegiate%20athletes%20to%20enhance%20their%20upper%20extremity%20performance.
  16. Freiberger, E., Cornel Christian Sieber and Kob, R. (2020). Mobility in Older Community-Dwelling Persons: A Narrative Review. Frontiers in physiology, [online] 11. doi:https://doi.org/10.3389/fphys.2020.00881.
  17. Hsu, S.-L., Oda, H., Saya Shirahata, Watanabe, M. and Sasaki, M. (2018). Effects of core strength training on core stability. Journal of physical therapy science, [online] 30(8), pp.1014–1018. doi:https://doi.org/10.1589/jpts.30.1014.
  18. Stins, J.F. and Emck, C. (2018). Balance Performance in Autism: A Brief Overview. Frontiers in psychology, [online] 9. doi:https://doi.org/10.3389/fpsyg.2018.00901.
  19. Zemková, E. and Ludmila Zapletalová (2021). Back Problems: Pros and Cons of Core Strengthening Exercises as a Part of Athlete Training. International journal of environmental research and public health/International journal of environmental research and public health, [online] 18(10), pp.5400–5400. doi:https://doi.org/10.3390/ijerph18105400.
  20. Leite, T.B., Costa, P.B., Leite, R.D., Novaes, J.S., Fleck, S.J. and Simão, R. (2017). Effects of Different Number of Sets of Resistance Training on Flexibility. International journal of exercise science, [online] 10(3), pp.354–364. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5609666/#:~:text=As%20practical%20applications,in%20goniometry%20assessment.
  21. Gong, J., Gao, H., Sui, J. and Qi, F. (2024). The effect of core stability training on the balance ability of young male basketball players. Frontiers in physiology, [online] 14. doi:https://doi.org/10.3389/fphys.2023.1305651.
  22. Indri Hapsari Susilowati, L. Meily Kurniawidjaja, Susiana Nugraha, Sjahrul Meizar Nasri, Pujiriani, I. and Bonardo Prayogo Hasiholan (2022). The prevalence of bad posture and musculoskeletal symptoms originating from the use of gadgets as an impact of the work from home program of the university community. Heliyon, [online] 8(10), pp.e11059–e11059. doi:https://doi.org/10.1016/j.heliyon.2022.e11059.
  23. Monteiro, E.R., Vingren, J.L., Corrêa Neto, V.G., Neves, E.B., Steele, J. and Novaes, J.S. (2019). Effects of Different Between Test Rest Intervals in Reproducibility of the 10-Repetition Maximum Load Test: A Pilot Study with Recreationally Resistance Trained Men. International journal of exercise science, [online] 12(4), pp.932–940. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6719818/.

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