Crunches are the most important exercise when it comes to training the straight abdominal muscles (m. rectus abdominis). It can be performed in different variants. The most basic you can see here.

Crunch, Weighted, Dumbbell
Crunch, Weighted, Dumbbell

Muscles involved



Correct execution of crunches

  • Lie on your back with both legs hip-width apart, so that knees and hips are bent and the lower back is resting.
  • Bend the ankles so that the toes point diagonally upwards towards the ceiling.
  • Now tense all of your abdominal muscles by imagining pulling your belly button “inward” and then begin to very slowly curl your torso forward.
  • As you do this, your shoulder blades will come off the floor and your upper torso will move forward-up a few inches.
  • While doing this, push your arms forward along your thighs (with your wrists bent towards you).
  • Your head will also roll forward minimally, but only enough to fit a fist between your chin and chest.
  • Hold the final position briefly, then move back, but do not lay down completely in order to maintain abdominal tension.

Common mistakes

  • Momentum: In crunches, the movement only comes from your upper body. You should not use your arms or legs to gain momentum as this will lessen the training effect.
  • Pulling your neck with your hands: This not only weakens the training stimulus, but also exposes the neck to an increased risk of injury.
  • Upper body straight: The upper body should not be straight during crunches. Rather, you move the upper body in a curve slightly upward.
  • Chin rests on chest: The chin should not rest on the chest during crunches. The head naturally extends the spine so that neither the head is on the chin nor the neck.

Tips to intensify crunches

  • To make the exercise more demanding, the arms can also be crossed on the chest or behind the head (= longer lever, more effort). In this case, however, be careful not to pull on the head.
  • You can grab a barbell plate or a dumbbell in front of your chest

Variants of crunches