Are Abdominal Crunches Useful For Losing Belly Fat?

Image by: FBellon
By Yuri Elkaim

Today I’d like to propose something that is perhaps a little controversial. And that is that abdominal crunches do not burn belly fat!

To understand why this is so, we must talk about two principles. The first principle comes from physics and it is known as “Work”. Work equals force times distance.

W = F X D

The second concept I want you to understand is that for every liter of oxygen you consume, you will burn approximately 5 calories.

We are going to use 2 examples to illustrate this.

Let’s look at the stability ball crunch or an abdominal crunch on the floor.

I think it’s safe to assume that you will cover a little less than one foot (distance) while doing a crunch, correct?

When you extend around the ball and finish in somewhat of a seated position, that distance represents one foot in our example.

I am going to assume the weight you are moving (the weight of your torso) is 40 pounds, considering you are only moving your upper body.

That means that the work being done is approximately 40 lbs x 1 foot. Usually you would measure this in Newtons-meters in physics but I am going to make this easy to understand by simply using lbs and ft.

So 40 lbs is the force and 1 foot is the distance, which gives us 40 “Newton meters”. I have fudged the data, but you get the idea.

Now, let’s look at the example of a full body exercise such as a clean & press. You start with the weights at floor level and end with them pushed above your head. It is an Olympic-type movement and I use a lot of them in my workouts.

In this case, let’s say that we have 2 dumbbells that are 25 lbs each and therefore a total weight of 50 lbs.

This time the distance you are covering (with the weight) is 7 feet. We are going to assume you are six feet tall in this example. So that the total distance from the floor to where you push the weights is 7 feet.

And This Is Where Things Get Really Interesting…

If we look at the equation of Work once again, we have 50 lbs x 7 feet, which gives us a grand total of 350 Newton-meters.

Look at the difference!

A crunch gives us 40 while a clean press gives us 350. If these numbers represent energy expenditure, which one would you rather do if we are talking about burning maximum calories?

I think the answer is obvious.

When it comes to losing belly fat (and overall fat) what it is boils down to is this..

How much work you do determines how many calories you burn!

A lot of people want to know how to get a six-pack without the pain and without the hard work. Well, you can’t.

You simply cannot get around doing work (exercise) and eating healthily for a flat stomach.

Abdominal belts, sauna belts, and little abdominal movements do not work because of the work factor; because of this basic equation. Hard work is how it works if you’re serious about losing belly fat.. and I know you are.

Oxygen Consumption and Burning Belly Fat

The second component to losing belly fat is that for every liter of oxygen you consume you burn about 5 calories.

With a full body movement (like the clean press, above), more muscles are required to do the work. And, therefore, you are going to need a lot more oxygen to supply those muscles.

That means that you are going to burn a lot more calories during your workout.

Conversely, abdominal crunches recruit very little muscle and thus required less oxygen. Thus, they don’t burn as many calories!

Crunches strengthen your rectus abdominis muscles (the 8-pack muscle) and that’s about it. There is very little energy expenditure when you do crunches.

So if you are spending your time doing endless amounts of crunches, not only are you wearing down your spine, but you are not going to lose belly fat because of the 2 simple principles we’ve looked at in this article.

On the flip side, a full body workout where you are unable to talk (ie. you’re huffing and puffing) is going to recruit more muscle, more oxygen, and thus burn more calories.

It will also raise your metabolism so that you continue to burn calories for several hours after your workout!

Now that’s powerful.

[Ed. Note: Yuri Elkaim is one of the North America’s leading fitness, nutrition, and conditioning experts. For the best workouts that will strengthen your abs and core without compromising your low back, be sure to check out his “Super Nutrition Academy”.]