Two of the easiest exercises that a person can do for strengthening the abdominal muscles are sit-ups and crunches. These exercises do not require any fancy equipment or a big place.

For many, these two terms are interchangeable. But there are specific physical differences that set these apart. For instance, unlike crunches, sits up are more intense and target additional muscle groups.

Let’s have a look at both and see how they are different.


Even though both crunches and sit-ups are abdominal exercises, there are vital differences.

A crunch is essentially a “half sit up” since it only focuses on abdominal muscles. Your lower part does not move for the entire duration of the exercise. Crunches isolate your abdominal muscles.

Crunches are great for getting that “six-pack,” but they are not holistic and do not burn fat.


Performing Crunches

  • To start the exercise, lie flat on the back with legs bent at knees and feet firmly on the ground. Place your hands either behind the ear or cross them over your chest
  • Raise the head and shoulders without moving the legs and feel the contraction of abdominal muscles. Do not pull your neck forward as it may strain the neck
  • Lower the head and shoulders down towards the starting position
  • Exhale as you raise and inhale as you lower the head and shoulders

Sit Ups

While crunches focus solely on abdominal muscles, sit-ups are bit more intense and involve chest, neck, abdominal muscles, lower back muscles, hip flexors, and lower leg muscles.

While a sit-up may look easy, but doing them improperly can result in severe injuries. The risk is so high that the US Army has decided to phase out sit-ups by late 2020.

To avoid any injury, a sit-up must be performed correctly. The basic rule is – perfect the form, start slowly, and increase the reps over time.

Performing Sit Ups

  • To begin the exercise, lie flat on the back with legs bent. You can also hook the feet for additional support. This, however, will result in focusing more on lower back muscles rather than the abdomen.
  • Place hands behind the head, or crossed above the chest, or flat against the sides. To ensure there is minimal involvement of back muscles, flex the neck slightly to tuck the head forward
  • Use the abdominal strength to curl the upper body forward until it is not touching the floor, and you are upright
  • Lower back slowly toward the starting position
  • Exhale while rising and inhale while going back to the starting position

The Difference

Both sit-ups and crunches are common abdominal exercises that focus on developing core strength.

Focus Area: While crunches focus exclusively on abdominal muscles, sit up target different muscle groups which also included lower back, lower leg, and hip flexors.

Posture: Having a proper posture is essential for any exercise, but it is necessary while doing sit-ups. Doing too many sit up too quickly in a wrong position can result in injuries and hyperlordosis.

To avoid these injuries, follow the guidelines given above, start slowly and aim at maintaining a proper posture to get the best and safest results.

Bottom Line

Merely doing crunches or sit-ups will not help in burning the fat. These along with a proper healthy diet goes a long way in attaining that flat and muscular ab you always desired for.