How to nail the perfect crunch and sit-up


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Doing crunches and sit-ups on a routine basis? Good for you! Now, are you doing them correctly? We hope so. Do your back, neck and abs a favor and follow these tips by Julie Erickson, owner of Endurance Pilates & Yoga in Arlington, Mass., and creator of Barre Boston. She explains the proper way to do a crunch and sit-up.

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The perfect crunch

In a proper crunch, the focus is on bending the upper part of the torso. A crunch mainly uses the upper connection of the rectus abdominus (abs) for mobility and the rest of the abdominals and core muscles for stability throughout the rest of the torso.

Things that can go wrong during a crunch are:

  1. Lifting with the neck muscles.
  2. Lifting with the shoulders.
  3. Lack of stability in the rest of the body.


To avoid this, focus on the following:

The hands should be behind the head and palm on top of palm without fingers linked. Why? Because it will open the chest, support the weight of the skull and pull the shoulders into their proper alignment prior to the upper torso lifting away from the mat.

The neck and spine should lengthen, not shorten as the head lifts away from the mat. Instead of jamming the head forward and pressing the chin into the chest, think of lengthening the neck, pulling the head away from the shoulders and continuing to keep that length while drawing the head away from the floor. The head should come into a lifted and supported position above the chest prior to the ribcage, and shoulder blades lifting away from the floor into the crunch.

The elbows should stay wide and the shoulders away from the ears. The upper back muscles and latissimus dorsi (i.e., broad shoulder muscles) are key players in the alignment for a proper crunch. In order to allow the proper firing pattern and strengthening of the core and abdominal muscles, the lats and upper back must do the job of maintaining the head, neck and shoulders in the proper alignment.

The return to a start position is just as important as the lift. Keep all of your muscles engaged throughout the entire exercise, never letting anything release or “flop” onto the floor.

What doesn’t move is as important as what does move. Part of the challenge in a crunch is to keep the part of the body that doesn’t move absolutely still throughout. Your legs should be drawn together, lower body still and stable, the lower part of the torso drawing in.

The perfect sit-up

A full sit-up will take a crunch and continue to bend the torso toward the legs until the upper body lifts away from the floor. When we add in this piece of the exercise, we add in more moving parts, less stability and strong muscles that like to take over for weaker ones. Things to keep in mind:

Ideally, the hands stay behind the head. This will disallow the shoulders, trapezius (i.e., neck and upper shoulder muscles) and chest muscles to stay in their proper place. A modification could be arms reaching long; however, this could allow for greater use of the shoulders. A full sit-up should only be performed after the mastery of the mechanics of the crunch.

The hip flexors and feet stay in a fixed position with the knees bent as the torso continues to lift. The hamstrings will work to keep the feet and legs in the fixed position, which will ensure that the abdominals are doing the work to lift the torso from the floor, not the hip flexors.

The spine lifts into a capital “C” position, not a lowercase “c.” The goal is to lengthen the spine, even as it flexes, so as the torso lifts, the space between each vertebrae increases and you pull the belly in and up, hollowing out the belly in the lifted position versus collapsing the ribs into the hips.

Every muscle stays engaged and works back to the start. Do not let go on the way down!