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Crunches: How To Do, Risks, Benefits,…

There are many different ways to improve your current exercise routine. What about doing crunches, what will the effects be?

Crunches are a popular exercise where you lie down on the ground and raise your shoulders while keeping your lower back on the ground.

This exercise is typically done to grow and strengthen ab muscles. For other fitness goals, there are many better exercise options.

Before you give this ab exercise a try, keep in mind that you generally can’t target fat loss in specific body parts. Crunches can be helpful for building abs but relatively bad for losing belly fat. If that is your goal you want to look for exercises that help you burn a lot of calories.

Whether you should add crunches or other alternatives to your routine depends on things like your personal situation, personal preference, and training goals.

How to do a crunch

For crunches you preferably want a yoga mat or other soft surface to lie on. To do a crunch take the following steps:

  1. Lie down on your back with your legs bent at the knees and your feet flat on the ground. You can place your hands next to your head, cross them over your chest, or put them anywhere else. The point is to not really use your arms or move them during the exercise.
  2. Slowly raise your shoulders from the ground as much as possible while keeping your lower back on the floor. Make sure you don’t use your arms but your ab muscles to do this movement. Move your head along with your shoulders while keeping it in a normal position.
  3. Lower your shoulders and head in a controlled motion until you are back in the starting position. If you plan to do more repetitions you can keep your lower back pressed against the ground with the help of your abs.

Keep your movements slow and controlled to make your abs really work hard and to avoid bad technique.

Make sure you don’t jerk your head forward throughout the exercise, especially if you put your hands behind your head. Also try to make sure your abs are powering the movement, not the momentum of your arms.

How to do a crunch

Regular crunch variations

Crunches with just your body weight and your arms against your chest are the standard version of the exercise. There are also a lot of crunch variations that can make the exercise easier, harder, or focus on different muscles.

Some people are not ready yet for full crunches. To work up to the full version you can consider only raising your shoulders a small amount. Another thing you can do is just tense your ab muscles.

Both of these will help you train similar muscles but at a less challenging level.

On the other hand, bodyweight crunches can become too easy. At this point, you may need to turn to other exercises or make crunches harder to keep seeing a lot of muscle growth and strength progress. Working to 100 crunches a day is usually not the best idea.

Making crunches harder at the right points in your training journey can also speed up progress compared to doing the regular bodyweight variation over and over.

A simple no-equipment way to make crunches harder is to stretch out your arms above your head. The laws of physics make it so that the movement becomes harder that way.

You can also do crunches on an exercise ball. One study observed more ab muscle engagement this way when the exercise ball was placed in the right position (1).

Besides that, the main way to make this exercise harder is to do weighted crunches. This is basically doing the same exercise but with extra weights or resistance to make it harder. You can hold weights like dumbbells, kettlebells, weight plates, grocery bags, etc. in your hands or against your chest.

Muscles worked with crunches

Crunches are mainly an ab muscle isolation exercise. This makes crunches more helpful for targetting abs compared to a more all-around core exercise like sit-ups.

The way you build muscle in places like your abs is by engaging these muscles so that they get damaged enough. This may sound counterintuitive but this damaging makes it so your body repairs these muscles, and adds a bit more to be better prepared to exert similar efforts in the future.

If you stick to exercises with the same weight, as your muscles become stronger this same effort may not damage your muscles enough to promote extra muscle growth.

By adding extra resistance to exercises like crunches you are better able to damage the muscles in a shorter amount of time. If you don’t overdo it, give your body enough nutrients, and give your muscles enough rest this can in turn lead to faster and more core muscle gain.

For both the bodyweight and weighted crunches, to build the most muscle mass you want to do about 4 sets of 10-40 crunches depending on how advanced you are.

Depending on your personal situation, workout plan, and training goals, crunches may be a good or bad addition.

Keep in mind that you have other core muscles like obliques that often play an important role too. Exercises that target both obliques and abs can be a better idea in some situations.

Crunches benefits

Some people question how useful this exercise can be but adding crunches to your routine can offer you some helpful benefits. Some of the most important ones include:

  1. Stronger muscles: Crunches are a type of resistance training that can help you strengthen your ab muscles and make them stand out more.
  2. Can help with losing weight: Doing crunches likely requires more energy than your regular daily activities. Extra muscle mass also helps with burning more calories. Both of these aspects can help with, but are no guarantee for, weight loss. Keep in mind that there are better exercise choices if weight loss is your goal.
  3. Improves mood: Exercise like crunches promotes the release of substances that help you feel good.
  4. No equipment or location required: Since crunches are a bodyweight exercise you don’t have to invest in equipment or be in a specific location. That being said, a soft surface like a yoga mat can make the exercise more comfortable.
  5. Improves sleep: Exercise like crunches can improve the quality and duration of your sleep which in turn offers many important benefits.
  6. Slows down aging: Crunches won’t influence how many days have passed since you were born. However, exercise can slow down the progress of certain aging markers that are correlated with negative health effects.
  7. May reduce or prevent back pain: Core strengthening exercises like crunches can reduce or prevent back pain (1, 2). If you currently have back pain you do want to be careful and talk to an expert before implementing this exercise.

While inevitably many workouts are better for some of these benefits than crunches, it is amazing that you can get so many important benefits from adding one activity to your routine.

Potential risks

The main thing to keep in mind is that crunches can be hard on body parts like your back, hips, and neck even if you implement the right technique.

If you are weak or sensitive in these body parts you may need to do other strengthening exercises first. Especially if you have any back pain, you may want to talk to your primary care provider before starting a new workout routine.

If you feel pain in any body parts it may be a sign you are overdoing it. In that case, you may need some rest, better lifestyle habits, a less intense workout schedule, or it may be a sign that crunches are not (yet) for you.

Crunch alternatives

While crunches can definitely be a great addition to your workout routine, there are also some alternatives available for training your core muscles. Some of these crunch alternatives include:

  • Bicycle crunches
  • Sit-ups
  • Leg raises on the captain’s chair
  • Compound core exercises
  • Flutter kicks
  • V-ups
  • Plank exercises

Which one of these options is the best depends on things like your personal situation, training goals, the equipment you have available, etc.


Many people will benefit from adding crunches with the right technique to their routine. You may need to make the regular version more challenging soon with crunch exercise equipment to keep seeing a lot of muscle growth and strength progress.

That being said, for goals besides strengthening your abs and making them stand out more, there are many better exercise options.

You also need to remember is that crunches can be hard on body parts like your back, hips, and neck even if you implement the right technique.

If you are sensitive or weak in these body parts you may need to do other strengthening exercises first. Especially if you have any back pain, you may want to talk to your primary care provider before starting a new workout routine.

Also keep in mind that consistency is an important factor for any workout plan. The more you love the exercise you do the easier it becomes to do it consistently. If doing crunches is a workout you love, great. If not other exercises can also offer a lot of benefits.

If you do decide to implement more crunches make sure you give your body enough nutrients, rest, and sleep to repair and grow your muscles.


Matt Claes

Matt Claes founded Weight Loss Made Practical to help people get in shape and stay there after losing 37 pounds and learning the best of the best about weight loss, health, and longevity for over 4 years. Over these years he has become an expert in nutrition, exercise, and other physical health aspects.