Exercise Want a Flat Belly? Stop Doing Sit-Ups!

Want a Flat Belly - Stop Doing Sit-ups

4 reasons why sit-ups are bad and what to do instead

As an experienced fitness trainer and nutritionist, I have been approached by hundreds of people, over the years, looking to change their bodies and improve their lives. 

One of the most common goals is fat loss, specifically in the belly area.

We all know that achieving and maintaining proper body weight is critical to overall fitness and health and it comes with the added benefit of looking great in that swimsuit!

So, how do we go about getting that lean, flat midsection?

Lots of sit-ups must be the answer, right? Everyone’s doing them.


Here are four reasons why sit-ups don’t work. This goes for those gimmicky ab devices and weighted ab machines, as well.

1. You are not burning belly fat

One of the biggest misconceptions around is that working certain muscle groups will burn fat from that area. Sorry, spot reduction is a myth.

Fat and muscle are totally separate, very different compositions.

When we do sit-ups, we work the underlying muscle, which may cause it to grow. If the outer layer of fat remains unchanged, it may be pushed out causing the waist to actually become bigger. Not the look most of us are going for, is it?

To burn fat, we need to burn calories. We need to get the heart going with movement. Sit-ups may do that to a small degree but even housework or gardening would be a better choice.

2. You’re wasting time

So, if burning calories is the key to burning body fat, what should we be doing instead to maximize our workout time?

Think C & C – compound movements and cardio.

Hit the weights! Compound exercises, meaning weight training using many muscle groups at the same time is key to efficiently shedding those extra pounds and shaping your body. Think big movements like the squat, lunge, deadlift and overhead press.

A well-designed weight workout, especially one with some fast-paced circuit training included can be a great fat burner. It’s the most effective method for this purpose and should be the priority, although I do recommend adding some additional cardio for fat burning, cardiovascular health, and conditioning.

I always advise people to try to find cardio activities they enjoy like swimming, cycling, tennis or simply walking, although many are quite content on a treadmill or elliptical trainer. We are much more likely to stick with things we like.

Using interval cardio training, meaning alternating between lower and higher intensities is a great way to strengthen the heart while burning fat.  

Whatever you do, get up and get moving!

3. You already have a “six pack”

We all have muscles called rectus abdominis. In most cases, they are hidden by a layer of body fat. Achieving a defined midsection is much more about revealing what’s underneath than building what’s already there.

Our abdominal muscles are designed to support the spine and keep it straight, therefore, exercises like planks and rollouts, put the body in a safer position. They work the transverse abdominis (the deeper muscles that hold the rectus abdominis in), the obliques and the erector spinae, building a strong core which helps our overall strength, stability, and balance. Since they have many progressive variations, they can be challenging and fun alternatives.

The most important piece of the puzzle is, of course, that dreaded four letter word, diet! A sensible eating plan is a must. Remember, you can’t exercise your way out of a poor diet.

4. You’re hurting your back

So now that we have established that sit-ups and crunches are not an effective, efficient way to trim down that waistline, let’s look at the most important drawback to this approach.

You may actually be doing serious and permanent damage to your spine.

According to Stuart McGill, professor of spine biomechanics at the University of Waterloo, “There are only so many bends or ‘fatigue life’ in your spinal disks. Inside each disk is a mucus-like nucleus,” he says, “and if you keep flexing your spine and bending the disk over and over again, that nucleus slowly breaches the layers and causes a disk bulge, or a disk herniation.”

The bottom line is that even those with healthy backs, using proper form may be doing more harm than good without even knowing it. On the flip side, strengthening the core with sensible, safe exercises can help to alleviate back pain

That is not to say there is no place for crunching movements in a routine. Minimal amounts of crunches, performed with strict form can play an important role in rectus abdominis development. Just remember they won’t get you leaner.


The sit-up is an inefficient movement at best and dangerous and useless at worst. It doesn’t burn belly fat and it may cause permanent damage to your back.  

So, I say, first things first. Let’s start by getting leaner and stronger.

Focusing on exercises that work the core as a whole, weight training with compound movements, cardio, and of course following a sensible eating plan is the recipe for a tight, toned tummy.

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