Sit-up vs Crunches Overview

3 min

Sit-ups and crunches are very similar exercises, with almost the same muscle motion. As such, I decided to write this Sit-up vs Crunches post.


Sit-ups work the neck, chest, hip flexors, abdominal and entire back muscles.

When doing sit-ups do the following:

  1. Lie down flat on your back, with your face facing the sky or ceiling.
  2. Bend your legs and place feet firmly on the ground to stabilize your lower body.
  3. Place your hands on your ears.
  4. Curl your upper body all the way up toward your knees.
  5. Slowly, lower yourself down, returning to your starting point.
  6. Repeat the motion again, for the specified number of reps.


Crunches work only in the upper abdominal and upper back muscles.

When doing crunches do the following:

  1. Lie down on your back, with your face facing the sky or ceiling.
  2. Bend your legs and stabilize your lower body.
  3. Cross your hands to opposite shoulders, or place them behind your ears without pulling on your neck.
  4. Lift your head from the ground.
  5. Exhale as you rise.
  6. Lower, returning to your starting point.
  7. Repeat the motion again, for the specified number of reps.


In this section of the Sit-up vs crunches overview, I show you the similarities between sit-ups and crunches.

Abdominal muscles

Both crunches and sit-ups work the abdominal muscles. Whereas crunches work the upper front abdominal muscles, sit-ups work the entire length of the front abdominal muscle.

Starting Positions

Both exercises start from a lying down position.

When doing the crunch the head is not allowed to rest on the ground, but when doing a sit-up, the head can reach and touch the ground, ever so slightly.


Both sit-ups and crunches have lots and lots of variations.

Some of the variations of the sit-up include the following:

  1. Oblique sit-up
  2. Floor sit-ups
  3. Bicycles
  4. Bench sit-up, etc.

Some of the variations of crunches include the following:

  1. Floor crunch
  2. Bench crunch
  3. Oblique crunch, etc.


Both crunches and sit-ups are notorious for damaging the back of those who don’t have proper form.

Care must be taken to do these two exercises, slowly at first, then increase the intensity, as stamina increases.

I also advise my clients not to engage in abdominal exercise, more than once a week, and at most twice.


Below I outline some of the main differences between sit-ups and crunches.

Target muscles

Whereas situps target the neck, chest, hip flexors, abdominal and entire back muscles.

Crunches work only the upper back and abdominal muscles.

Muscle motion

The second garring difference between sit-ups and crunches is muscle motion during the workout.

Whereas crunches have a short movement from start to finish, sit-ups,on the other hand, have a longer range of motion.


Are sit-ups better than crunches?

There is a reason why the term bodybuilding was coined.

I always tell my clients this, the back is the foundation of your body, whereas the side abdominal muscles are the walls, and then finally, your front abdominal muscles function as the roof of your body.

Without a solid foundation (back), you will have a hard time getting perfect six-pack abs.

Now is where everything gets interesting, sit-ups work your front abdominal muscles, side abdominal muscles, and your back.

Whereas, crunches only work your front abdominal muscle. As such, the sit-up is a better workout in general in your quest to achieve six-pack abs, since it works the back (the foundation of your body), the side abdominal muscles (the walls of your body), and the roof (which is the roof of your body).

What is the difference between sit-ups and crunches?

The main difference between sit-ups and crunches is the target muscle and muscle motion during the exercise.

Do sit-ups and crunches really work?

It depends on whether the person doing the sit-up or crunch, is an amateur or novice.

Contrary to popular belief, there are no bad exercises.

In fact, sit-ups and crunches, like anything in life, has to be mastered, to get the best results.

The most important thing, during a workout, is mastering form. Without form, you can injure yourself.

Sit-ups and crunches are notorious for being had to master and get proper form.

Novices should adopt easier exercises like squats, which outperform both crunches and sit-ups when building six-pack abs.

How many crunches equal a sit-up?

A definitive answer cannot be given as to how many crunches equals a sit-up. These exercises are completely different in their own rights.

On average, sit-ups outperform crunches by a factor of 3:1.

It is better to do 1 sit-up than to do 3 crunches.

See also: How to lose 30 pounds in 30 days


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