Under your skin, you have a layer of fat (Subcutaneous Fat).
This is the bit you are aware of and desperately want rid of. It’s the bit that jiggles.
Behind that are your abdominals (rectus abdominis).
Although there is often talk of your upper abs and lower abs, it’s really just one sheet and it’s impossible to work one without the other being involved. There are also your obliques and transverse abdominis crossing over in this area, with each doing a different job of supporting your ‘core’.
I’m not going to go into major detail, as it’s not important for the point I’m making, but you can see on the diagram where they are all located when looked at in profile.
Behind that you will find visceral fat.
This is the fat you ‘should’ be concerned about as an excess of this kind of fat is extremely dangerous and can be life threatening.
Let’s say you do focus on abdominal crunches in an attempt to burn off that fat.
Firstly, crunches are working a very thin sheet of muscle and not moving it terribly fat. It is a muscle area that recovers quite easily as a result and therefore does not cause much in the way of energy expenditure.
You may feel it is hard and that you are working hard, but the reality is, it’s uncomfortable, but not a large energy burner. Therefore, the number of calories burned will be tiny compared with working larger muscle groups.
The muscles being worked will get fuller.
So, have a look at the diagram. What would happen if your abdominal region got fuller?
It would push the fat out further.
So, we’ve not burned off much, if any fat, but we have pushed it out a bit.
Rather than getting a flatter tummy, you have now got a bigger one.
Add to that the fact that you now not only have a ‘load’ at the front that is likely affecting your posture somewhat (depending on the level), but you have now strengthened and tightened your abs in a way that, if not countered on the back end, will cause your posture to get worse.
It’s a no-win situation!
Nothing about this is good based on the goals you set out to achieve.
That doesn’t mean abdominal exercises are useless.
Even though doing crunches is making things worse and pushing you away from your goals, that doesn’t mean direct abdominal work is without merit.
So long as the goal is to strengthen your mid-section and improve your posture, as a supplement to a strong approach, working directly on your abs can be beneficial.
A stronger mid-section will allow you to do more energetic things in your day to day life, without the same level of injury risk.
By having a better connection between your lower and upper body, doing compound movements, such as squats or deadlifts, are going to be easier, more efficient and, again, allow you to do more.
Even if your approach involves elements of cardio, having a better posture is going to make those activities more beneficial, allow you to circulate oxygen more easily and be less prone to injuries.
As for crunches, they do have a place
If you are getting toward that lean stage, there isn’t much fat left and your abs are starting to show, you’ll have a lot more to show off if you have well worked abs.
Just keep in mind, this is going to have no impact until that layer of fat is gone and these exercises are not going to help do that. But, once you are at that stage, perhaps some cosmetic training is warranted. You will have worked hard to get there, so you should make the most of it.
Remember, however, your body is more than just aesthetics and there is no point looking good if you are in pain as a result. So be sure to keep your training in balance and if you are going to strengthen an area at the front, you must ensure the opposing muscles at the back are just as strong.
This may show that, direct crunches are not the solution to a flatter tummy, so what is?
In a nutshell, doing bigger movements, using more muscles and a complimentary diet is going to have a much more positive effect on your results.
Have a look at this article on the best way to tone up to get a full rundown of how to approach this.