Will Sit-ups give me the flat stomach I desire by Summer?

Posted By irvinechiro / Date Posted: 2015-08-18

One of the most frequent questions I get asked in clinic is “are Sit-ups good for me?”, or worded another way “I do 500 Sit-ups a day, is that ok?”

General Lumbar Spine Anatomy

Lumbar spine

To understand what is happening when we perform a sit-up or any other exercise that requires spinal flexion such as a crunch or leg raises, there is a certain amount of anatomical knowledge we need.

Most importantly we need to understand the anatomy of the lumbar spine. There are 5 vertebrae called L1, L2, L3, L4, L5. There is a disc between each pair of vertebrae. There are nerves that come out between each pair of vertebrae. There are also layers upon layers of connective tissue and muscle on top of that. No need to go through the details of these layers, just understand that is a complex web of tissues.

General Disc Anatomy

There is a disc between each set of vertebrae and the disc is basically made up of two things, an outer circular portion called the annulus and an inner squishy part called the nucleus pulposus. A disc herniation occurs when the outer circular part has tears in it and then the squishy inside squirts out. You can also get tears in the outer circular part without the squishy nucleus coming out.

Interestingly only the outer 1/3 of the disc can cause pain. So you could potentially damage almost 2/3 of it without feeling pain. Most people with mild to moderate disc injuries report that the injury happened without doing anything. I explain that this is often quite literally the straw that broke the camel’s back. Quite often patients will report that they injured their back “just picking up a pencil”, or “I just bent forward to tie my shoelace”. These seemingly innocuous activities may seem like nothing but they are the build-up of many micro-traumas to the disc. Misusing the lumbar spine over an extended period of time is the most common reason people injure it. It isn’t from one wrong move.

Logic of Doing Sit-ups

What do you care more about? How many sit-ups you can do or how flat your stomach is? If you want to build up endurance for doing many sit-ups then keep doing them, if you want a flat midsection stop doing them.


One of the world’s leading researcher’s Dr Stuart McGill (not the cricketer) has published extensively on the subject of core strengthening. What McGill’s research tells us is that exercises that require high repetitions of lumbar spine flexion and extension (low back rounding to fully extended) have the greatest potential tear that outer circular annulus layer of your disc, cause disc herniations, and can damage spinal ligaments. I can tell you from first-hand experience, both because I had these issues and I treat people who have these issues, that those things are nasty! 

In the lab, when using spinal specimens, McGill’s research showed that

"the most reliable way to herniate a disc in the low back was to basically put it through lots of reps of sit-ups"

My Thoughts

I have probably done more sit-up’s than anyone reading this so it was hard for me to read this research and take it on board to start doing things differently. In an endeavour to leave you with some hope of still gaining that flat midsection I will give you my top 4 core/mid-section exercises that will also help you stay injury free. All of these exercises are about quality not quantity, so be sure to do them as intensively as you can without putting your precious spine at risk.

1. Dead Bug

Begin lying on your back with your hands extended above you toward the ceiling.

Bring your ankles, knees, and hips up to 90 degrees.

Exhale hard to bring your rib-cage down and flatten your back onto the floor (if this is comfortable for you), rotating your pelvis up and squeezing your glutes. Hold this position throughout the movement. This will be your starting position.

Initiate the exercise by extending one leg, straightening the knee and hip to bring the leg just above the ground and at the same time raising your arm above your head. 

Maintain the position of your lumbar spine and pelvis as you perform the movement, as your back is going to want to arch and ribs will want to flare. 

Stay tight and return the working leg and arm to the starting position.

Repeat on the opposite side, alternating until the set is complete.

A starting point would be to complete around 3 x 30 secs static hold in the starting position, progress this until you can hold for 3 x 1 mins. Once you can complete this then begin the movements as described above.

2. Side Plank

Lie on side on mat. Place forearm on mat under shoulder perpendicular to body. Place upper leg directly on top of lower leg and straighten knees and hips.

Raise body upward by straightening waist so body is rigid. Hold position. Repeat with opposite side. Ultimate goal is to be able to hold both sides for 2 mins each, however to begin with try and complete 3 x 30 sec holds and work your way up.

3. Plank

Lie face down  on mat. Place forearms on mat, elbows under shoulders. Place legs together with toes on floor. Raise body upward  in a straight line. Hold position. Ultimate goal is to be able to hold continuously for 2 mins, however to begin with try and complete 3 x 30 sec holds and work your way up.

4. Quadruped

Kneel with both knees and both hands flat on the floor (Starting Position). Simultaneously raise one arm and the opposing leg to the horizontally outstretched position and hold for the desired time period (Finishing Position). Return back to the starting position and repeat with the opposing arm and leg.

Complete 3 x 8 each arm or until fatigue. The way I describe this exercise is to feel like your core muscles are fighting with your arms and legs to not let them move. This should ensure the muscles are working.

Many variations exist for this exercise and you can scale it up or back from this in many ways. Consult your Chiropractor for help in perfecting these. Performing these exercises daily should not only give you a bullet proof lower back but it may also give you that flat midsection you are after. 


In summary there are only 2 ways to get better abs - Muscle hypertrophy and decreased body fat. So if you haven’t already, go back and read through my other blog posts on nutrition to get some ideas on how to decrease body fat.

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