Crunches are one of the most popular exercises for the abs. Here you can find out what the abdominal exercise is really good for, how to do it correctly and which variants there are.
The crunch is an exercise for straight abdominal muscles and a popular alternative to sit ups. During the exercise, you crunch or press your abdominal wall together: from the supine position, you lift your upper body slightly off the floor and pull the torso towards your legs using the strength of the abdominal muscles – without straightening yourself completely.
Crunches can be performed statically or dynamically: in the static variant you hold the abdominal tension for a certain time, in the dynamic crunch you raise and lower your upper body for as many repetitions as you like.
Advantages of crunches as an exercise for the stomach: It is easy to perform, back-friendly and you do not need any equipment. Therefore it is ideal for a pure bodyweight training or a beginner home workout.
What is the difference between crunches and sit ups?
In addition to crunches, sit ups are a popular abdominal exercise that no athlete can avoid. Their explanations are similar: Both exercises start in the supine position. When doing the crunch, you only lift your upper body slightly off the floor. In contrast, the goal of sit ups is to sit up completely.
You can get into an upright seat from the supine position by moving your torso towards your thighs and bending your hips. Sit-ups therefore also train the hip flexors, while crunches specifically activate the straight abdominal muscles.
Sit ups are considered more challenging because performing correctly requires more core tension than crunches. For this reason, beginners are often advised to start with the exercise crunch or variations of it.
How effective are crunches?
Crunches are one of the isolation exercises. Isolates because you are training a specific muscle group, namely the straight abdominal muscles. In contrast, compound exercises like squats or pull-ups activate several muscle groups at the same time.
A well-structured training plan should always contain a mix of compound and isolation exercises. So don’t focus exclusively on crunches, but also consider other exercises for your back, upper body, arms and legs in order to train your body holistically.
Crunches specifically activate the core of your body and, if performed correctly, set stimuli for muscle building. Strong abdominal muscles make perfect sense: Together with the back muscles, they stabilize and relieve the spine. You can improve your posture through abdominal training with crunches, counteract a hollow back and prevent back pain. Plus: A trained core ensures more balance and body tension, which you can benefit from in all sports – regardless of whether weight training, running or yoga.
Important for everyone whose goal is a visible six-pack: Your abs training is not primarily responsible for this. Because with this you strengthen your muscles, but you cannot specifically lose belly fat. This only works with the right diet. It is the driver for a defined core.
What do you workout with crunches?
The focus of classic crunches is on the straight abdominal muscles, but the oblique and deep-seated muscles of your core are also trained.
Primary target muscles:
- Rectus abdominis / straight abdominal muscle: The rectus abdominis is optically responsible for the six pack and an important postural muscle. The straight abdominal muscle ensures that you can pull your chest towards the legs when you crunch and thereby bend your torso.
- Musculus pyramidalis / pyramidal muscle: The pyramidal muscle is a triangular skeletal muscle that belongs to the anterior or middle, deep-lying abdominal muscles. It strengthens the connection between the abdominal and the pelvic floor.
- Musculus obliquus internus abdominis, Musculus obliquus externus abdominis / Inner and outer oblique abdominal muscles: The lateral abdominal muscles are responsible for the rotation in the upper body and contribute to a narrow waist and defined abdominal muscles. They are also partially activated during the crunch exercise.
Can you lose weight with crunches?
Crunches ensure strong abdominal muscles, but are no guarantee for a visible six-pack. Diet and a negative energy balance are more critical than exercise to lose belly fat. Still, you can use exercises like crunches to increase your calorie consumption. Because: The more muscle mass you have, the higher your basal metabolic rate.
How much energy you burn while exercising depends on many factors – including age, gender, weight, genetic predisposition, as well as speed, breaks and repetitions.
Our tip: The HIIT training method is ideal for boosting your fat burning and working on your six pack at the same time. Crunches and variations are a popular exercise in high-intensity workouts.
How many crunches should you do daily?
The right amount is also crucial for abdominal muscle training. In order for muscles to grow, they not only need regular training stimuli, but also sufficient time to regenerate.
Instead of training your abdominal muscles with crunches every day, it is better to do 4 x 25 repetitions three to four times a week. In addition, you train your stomach with most full-body exercises such as squats, push-ups or lunges as well as with endurance sports. It is all the more important to pay attention to break times and to support your body in regenerating. For example, with our Recovery Aminos, which thanks to quickly available carbohydrates and essential amino acids get you ready for the next session.
How to do crunches correctly?
If you want to do crunches correctly, the following step-by-step guide will help you:
- In the basic position, you lie on your back and bend your legs at a 90 degree angle. Put your heels up. You should just about be able to touch it with your fingertips.
- Make sure that your lower back stays in contact with the ground throughout the exercise. To do this, press the tailbone into the mat.
- Bring your hands to your head, fan your elbows wide, and pull your shoulder blades back and down so that your upper back is straight. Alternatively, you can cross your arms over your chest or stretch out to the sides of your upper body.
- You look up at the ceiling. The head and neck remain in line with the spine. A fist fits roughly between your chin and your chest.
- Now pull your belly button under your ribs and create tension in the trunk. With the help of the straight abdominal muscles, lift the upper back including the shoulder blades off the floor – crunche or press the stomach together towards the legs. Exhale as you go.
- Hold the tension and lower yourself in a controlled manner while inhaling, keeping your upper back and shoulder blades constantly in the air.
Bring variety to your ab training with our four crunch exercises. For more intensity or variety, you can of course include dumbbells, kettlebells, resistance bands or other tools in your workout at any time.
Heel Tap Crunch
Start in the basic position: Lie on your back, legs at 90 degrees, put your heels up so that you can just touch them with your fingertips. The arms are stretched out sideways. Build abdominal tension and lift your head and upper back slightly off the floor, like with a classic crunch. Now rotate your upper body from right to left so that you alternately touch your ankles / feet with your fingers. The movement is similar to a windshield wiper. In this crunch variant, the lateral abdominal muscles are particularly active.
Crunch with a twist
Get into the basic position with your hands on your head. Lift the upper back off the floor. Now bring one knee towards your stomach and touch it with the opposite elbow by twisting your upper body to the side. Use the strength of your straight and lateral abdominal muscles, being careful not to pull your head. Find your way back to the starting position and repeat the exercise with the other side. Then always twist and crunch alternately.
Lie on your back and bring your hands to your head. This time your legs are raised, thighs and lower legs form a 90 degree angle, your knees are above your hips. Extend one leg, bringing it towards the floor without putting it down. At the same time, turn your upper body to the opposite side and touch your upper knee with your elbow. Bend your straight leg again and repeat on the other side. Get into a flowing movement, like cycling.
Start lying on your back with your legs stretched out on the floor. Bring your hands to your head or place them under your lumbar spine as a support. Build abdominal tension and lift the upper back. Now draw your knees at an angle towards your stomach and then bring them back to the floor in a controlled manner without putting them down. Make sure that your lower back stays on the floor and that you don’t make a hollow back. Increase the intensity by doing the exercise with your legs fully straight.
Common crunch mistakes
The right technique is crucial so that the sweaty sessions on the mat are worthwhile and you benefit from the positive effects of your abdominal training. The following mistakes often happen when crunching – avoid them in the first place:
You crunch with momentum
If you work with momentum instead of the strength of your abdominal muscles, you risk putting unnecessary strain on your back. It often happens that exercisers bring too much speed into the exercise and let themselves fall back on the floor. Tension is lost and it is not the abdomen but the hip flexor that is activated. Make sure you do a controlled execution, keep your stomach tension and only move your upper back.
You come up too far
The further you go with your upper body in the direction of your legs, the stronger the hip-flexing muscles are. In sit ups, that’s what you want. For crunch, on the other hand, the upper body should only be raised enough from the floor that your lower back is still touching the mat. This way you leave the work entirely to the abs.
You work with your shoulders
The most important rule when crunching: keep your stomach tension! If this is not (yet) strong enough, it can happen that you only lift your shoulders off the floor and become round in your upper back. Press your lumbar spine into the mat and feel your belly button pull under your ribs. Before you start, deliberately pull your shoulder blades back and down.
You pull your head
A common mistake when crunching is that the lack of abdominal tension is compensated for by tugging on the head. But this increases the pressure on the cervical spine. Instead of bringing your hands to your temples, you can extend your arms to the sides of your upper body or cross them in front of your chest. In any case, make sure that your neck and head stay straight in line with your back. To control your posture: a fist fits between your chin and sternum.
You hold your breath
Abdominal muscle exercises quickly tighten your breath due to the great tension in your upper body. As soon as you find yourself holding your breath, pause briefly and find your even breathing again: breathe out when standing up, breathe in when lowering.