How hard can breathing be anyway?
You very simply breathe in and breathe out, this is something you are good at because you have been doing it all of you life.
But try scuba breathing underwater and it not that easy or simple anymore and you need a little more knowledge than just breathing in and breathing out.
Providing the scuba diver with air to breathe doesn’t guarantee the diver will have a safe and enjoyable diving experience. There is more to the process than that.
If someone stands in front of you and gives you a little push on the your chest. Your will tend to fall backward a little. But if you have someone standing in the back of you and pushing forward at the same pressure, you will remain stationary. You will just feel a little squeezed by the two forces.
The same thing is happening when you are underwater, only the pressure or force is coming from all sides at the same time. But the pressure is not coming from inside your body. The rigidity of your rib cage, your muscles and tendons are providing an “oppositely directed force”. If we didn’t have this protection, the body would just collapse under the pressure.
Your body has to push outward to counteract or balance the inward pressure. Your ribs and muscles are flexible enough to collapse inward a very short distance, than they gain enough rigidity to balance the pressure. This causes the lungs to compress a small amount.
Expanding your lungs becomes more difficult as you dive deeper because of the added water pressure.
Another reason for your difficulty is because air is somewhat easy to compress. It takes considerable force to compress water. This causes the air in your lungs to also compress a little.
By expanding your lungs against that small collapse and the compression of the air, this enables you to breathe properly and inhale enough air to supply your body with the much needed oxygen.