Why Crunches Are A Horrible Stomach Exercise

Sit ups or abdominal crunches – whatever you decide to call them they’re one of the worst exercises for your stomach. This month’s Workout Of The Month is dedicated to why you should shed crunches from your stomach exercise routine forever.

Crunches and Abdominal Muscles

Some Workout Of The Month articles feature how to do a specific exercise, others talk about the benefits of a type of activity, but others sometimes explain why a certain exercise should not be done. Sit ups fit into the category of an exercise that should not be done. To start with why let’s break down the muscles involved with abdominal crunches:

Rectus Abdominis: You know it as “abs” – they’re a small sheath of muscles that run vertically along the abdomen that chicks love and what guys want to have. They’re responsible for helping you literally, sit up.

rectus abdominis sit ups

The much coveted, rectus abdominis.

The rectus abdominus is the pretty much the main muscle that gets worked out when doing sit ups (4). Sure, there are a couple of other small muscles in your legs in spine that get a hint of a workout, but they don’t take the main brunt of the activity. Speaking of that spine…

Why Sit Ups Are A Terrible Abdominal Exercise

You might be wondering why abdominal crunches might be a bad exercise if abs are so great. Well the key to the answer lies in your lumbar spine in your lower back. Two things happen to your body when you perform a sit up. When you first begin the movement, your spine hyperextends. When you’re half way through the movement (the actual sitting up part of the exercise) your spine becomes hyperflexed. This places a tremendous amount of pressure on your lumbar spine and specifically between the disks between those vertebrae (1,2,3,4). Anyone who has ever had a slipped disk or bulging disk in the spine can know how excruciatingly painful such a thing is. Chances are pretty good that anyone reading this has at least known somebody who has had a slipped, or bulging disk.

lumbar spine abdominal crunches

The lumbar spine is made up of five vertebrae with disks in between each piece of bone.

An Exercise That’s Better Than Sit Ups

swiss ball plankTrying to build a strong core and a great looking stomach? Try the Swiss Ball Plank instead. Research has shown that this exercise is 50% more effective in targeting abdominal muscles than sit ups are (5). What’s even better is that they also target core muscles in the spine (which sit ups don’t). More of the benefit and less harm on the spine. What’s not to like?

The Bottom Line Of Sit Ups As An Exercise

When doing any exercise you always have to look at the risk versus the reward. Why bother with an exercise that places so much stress on the lower back when there are other core exercises that can more effectively target muscles in the abdomen, hips, and back to build strength and help relieve back pain – not increase the risk of it. It absolutely boggles my mind why athletic professionals still have people do sit ups as a core exercise. If you’re an older person trying to preserve your back or a younger person trying not to do damage to your back, sit ups are not the exercise you should be doing. Even if there was a “safe” way to perform a sit up there is still no point in doing them due to the fact that there are more effective abdominal exercises out there.

Discussion: Are you a fan of sit ups? Why or why not?


1. Benedict, T., Childs, J., Fortenberry, A., Mcqueen, R., Morris, J., Teyhen, D. “Effects Of Sit-Up Training Versus Core Stabilization Exercises On Sit-Up Performance.” Journal Of Applied Science. Nov. 2009. Web. Jan. 20, 2014.
2. Axler, C. McGill, S. “Low Back Loads Over A Variety Of Abdominal Exercises: Searching For The Safest Abdominal Challenge.” Medicine and Science In Sports and Exercise. June. 1997. Web. Jan. 20. 2014.
3. McGill S. “The Mechanics Of Torso Flexion: Situps and Standing Dynamix Flexion Maneuvers.” Clinical Biomechanics. June 1995. Web. Jan. 20. 2014.
4. Figura, F., Marchetti, M., Ricci, B. “Biomechanics Of Sit-Up Exercises.” Medicine and Science In Sports and Exercise. 1981. Web. Jan. 20. 2014.
5. Ayson, E., Batt, J., Davis, N., De Leon, G., Laymon, M., Lohman, E., Payken, C., Petrofsky, J., Roark, H., Tran, T., Vigeland, K. “Core Muscle Activity During Exercise On A Mini Stability Ball Compared With Abdominal Crunches On The Floor and On A Swiss Ball.” Journal Of Applied Research. 2007. Web. Jan. 20. 2014.