Crunches: Proper Exercise Technique

This exercise has many variations, so you can easily find the right option for youThis exercise has many variations, so you can easily find the right option for you



If you want to build sexy six-pack abs, you need an effective abdominal exercise and a suitable diet. Crunches are the most popular abdominal exercise.

This exercise is easy and very effective. It can help you build six-pack abs as well as tighten your belly by accelerating the fat-burning process. To perform its classic variation, you need neither additional equipment, nor exercise machines.

You should note that it is not recommended for everybody. Before you begin to master the technique of crunches, you should consider the contraindications. They include the presence of:

  • herniated discs;
  • osteoporosis;
  • osteochondrosis;
  • heart problems;
  • respiratory system disorders.

Also, pregnant women should not perform crunches.

What Muscles Work?

The exercise involves the entire abs, but it works primarily the upper abdomen. The main thing is to perform it with proper form, otherwise, there won’t be any results.

Crunches recruit the following muscles:

  • rectus abdominis muscle;
  • oblique abdominal muscles;
  • muscles of the middle and lower back.

Exercise Variations

The classic variation of the exercise is performed lying on your back on a mat or on a flat bench with your knees bent. Beside this option, there are many others:

Ab Machine CrunchesThis is another good option for those who work out in the gym. Machine exercises allow you to adjust the load, and the mechanism is designed in such a way that it is quite difficult to perform the exercise with improper form. This means that your abs get a good load in any case, so this variation is suitable for beginners. There are horizontal and vertical ab crunch machines, that is, to perform the exercise in a lying or sitting position, respectively. They differ in the nature of the load

Type Brief description
Incline Bench Crunches This type of crunches works out the lower part of the rectus abdominis muscle. To perform the exercise, you need to lie down on a bench so that your head is below the level of your legs. Also, in this position, it is more difficult to lift the body up, so the muscles get a greater load
Gym Ball Crunches They are performed similarly to the lying-on-the-floor crunches, with the difference that you should lie with your back on a gym ball and your feet on the floor. While lowering the body down, you can stretch it well, thereby increasing the range of motions
Legs Up Crunches They are performed lying on a flat bench or on the floor similarly to the classic crunches, with the only difference that your feet should be elevated off the floor with a 90 degree bend at your hips and knees during the entire set. Your hips should be positioned vertically and your lower legs – horizontally
Weighted Crunches These crunches are suitable for those who need a larger load. A weight plate or a dumbbell of suitable weight are usually used as additional weights
Cable Machine Crunches You should grab the handle of the cable machine, kneel in front of it, and start to bend and extend your back. At the moment of maximum contraction of the abdominal muscles, your hands should be at the back of your head; when extending the body, they should be above your forehead
Oblique Crunches You should start lying on your back with your knees bent and your hands behind your head. While crunching up, you should bring your elbow towards the opposite knee. If your hands are crossed over your chest, you should bring your elbows towards your thighs. This variation of the exercise allows you to work your oblique abdominal muscles. It is totally up to you, whether they need to be worked out. Girls should note that if the oblique muscles increase in volume, the waist increases as well, and the torso may look masculine

These exercise variations differ from one another in the load they exert on the abdominal muscles. Besides, the anatomical features of the body are also important: different people find some types of crunches more suitable and effective for them than others. Ideally, you should try them all to find the best ones for you. You can start with the classic variation.

Another point to pay attention to is the arm position. You can cross your arms over your chest or place them behind your head and clasp your hands on the back of your head. The first option is easier, so it is suitable for beginners. To increase the load, you can use the second option.

There is one more complicated option that, however, is used rarely – the extended arm crunches. To perform them, you need to cross your wrists and extend your straight arms forward above your head.

It may be interesting for you: "Reverse Crunches Technique".

Proper Technique

Here is the classic crunches proper form:

  1. The starting position: lie down on your back, bend your knees at a 90 degree angle, place your feet on the floor, cross your arms over your chest or place your hands behind your head.
  2. On an exhale, perform a crunch by bringing your shoulders toward your hips.
  3. On an inhale, slowly return back to the starting position.
  4. Complete the required number of reps, rest for half a minute to one minute, and proceed to the next set.

The Number of Reps

You should choose the number of reps and the load according to your workout goals. If you want to build six-pack abs, you need to perform three or four sets of 8 to 15 reps. In this case, you will probably need to use additional weight. For this purpose, you can take a suitable weight plate or a dumbbell. In the gym, you can increase the load by doing the exercise on an ab crunch machine.

If your goal is to accelerate fat-burning process in the abdominal area and tighten your belly, you need to complete 25 or more reps. The number of sets should be also increased to five or more..

Common Mistakes

Crunches can be performed both by men and womenCrunches can be performed both by men and women

The most common mistake that is made by almost every beginner is performing body raises instead of crunches.

In crunches, the body seems to be hunched and the torso goes toward the hips, but in body raises, the back remains straight and the shoulders go toward the knees.

With such a technique, abs are not engaged at all. You can perform the crunches in this manner for months and even years, but never get the desired results.

You should remember about proper pacing. The faster you perform the exercise, the worse the target muscle fibers are involved. Besides, you should avoid the appearance of inertia to pass every centimeter of the range of motion due to the quality tension of the abdominal muscles.

Also, when performing this exercise, many people tense their necks and press their chins to the chest. You should not do it, because this is an extra load that should be avoided.

Besides, improper breathing is a big problem for many people. You need to take a sharp and a really powerful exhale when you do a crunch, to exert the maximum load on the rectus abdominis muscle. Feel free to breathe loudly, even if you work out in the gym, because due to this, your ab workouts can be really effective.

Relaxation of the abdominal muscles in the peak extension movement is also a common mistake. If you keep your ab muscles in tension throughout the whole range of motion, the effectiveness of the exercise increases twofold.

Interesting Facts

Use different types of crunches in your workouts to achieve good results as soon as possibleUse different types of crunches in your workouts to achieve good results as soon as possible

American scientists from the laboratory of biomechanics at the University of San Diego conducted research on the abdominal exercises. They used electromyography to assess the load the muscles get during exercise.

In their top-7 exercises, the extended arm crunches are in sixth place, legs up crunches are in fourth place, and the third place is occupied by gym ball crunches.

Captain’s chair crunches and bicycle crunches that are the most effective ab exercises, took the second and the first places, respectively.


Crunches are an effective abdominal exercise that allows both building six-pack abs, and tightening the belly. The exercise engages primarily upper abs, but it can be used to work out all areas of the abdomen.

To increase the effectiveness of your workouts and achieve excellent results, you should not forget about the basic rules:

  1. You should choose the appropriate exercise variation, as well as define the load and the number of reps.
  2. Perform the crunches, not body raises.
  3. Take a powerful exhale when you do a crunch to exert the maximum load on the abdominal muscles.
Shesternenko Alexander
Fitness trainer, group instructor, dietitian
  • Counsels and educates on proper nutrition principles, body weight correction, and adjustment of individual diets and diets during pregnancy;
  • Develops meal plans that meet nutrition goals and dietary needs for obese and underweight people;
  • Specializes in modern functional testing techniques in sports, athletic recovery, sports supplementation, pharmacological support, and actual women's problems in sports;
  • On the website, provides analysis of different dietary schemes, reviews modern training techniques and effective exercises.


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