Terry pushes the "bad air" out.
Breathing is such a natural activity that we seldom give it thought. The only time we even become conscious of it is when we're breathless from exertion or, well, panic. Or in the case of swimming, sometimes both at once.
There's probably a greater range of breathing skill in swimming than in any other activity. Elite swimmers can breathe effortlessly while maintaining perfect form at maximum exertion and world-record pace.
Seasoned open-water swimmers can do the same with waves or chop smacking them in the face or a pack of churning swimmers at their elbow. At the other extreme, novices may be unable to experience any comfort so long as any part of their face or head is in the water and the challenge of getting air is so all-consuming that they have no presence of mind left for focus on form.
Breathing is unquestionably the most fundamental of all swimming skills. If you can learn to do it nearly as well and automatically in the water as on land, it helps calm and focus you to work on basic skills. It also provides the aerobic capacity to swim long distances and fuels the power to swim at maximum speeds.
Finally, the swimmer who masters Aquatic Breath Control can use breathing skills just as effectively to relax, improve their ability to concentrate and deepen self-awareness while working on skills, and to recover more fully and completely from any level of exertion. Since you have no choice BUT to breathe while swimming, why not choose to become a true master of Aquatic Breath Control?
Bad Air Out, Good Air In
For most folks, the most instinctive way to breathe is to pay attention to the inhale; the exhale is just an afterthought. In swimming, as well as other activities that involve enough exertion to lead to breathlessness, it should really be the opposite. Focus on the exhale; let the inhale take care of itself.
Here's why: Each time we take a breath, the air that goes into our lungs is about 21 percent oxygen and the barest trace carbon dioxide. The air we exhale is about 14 percent oxygen and nearly six percent carbon dioxide. So, when we feel "out of breath" it doesn't mean we're suffering a lack of oxygen since we consume only about one third of the oxygen we take in. Instead, that breathless feeling is caused by increased carbon dioxide in the bloodstream.
Thus, to maintain a sense of relaxation and comfort, you should focus mainly on exhaling, since that will clear accumulated carbon dioxide more effectively. You can heighten your awareness of the distinction between inhale-focus and exhale-focus through a series of exercises we might call "inside-out breathing."
You can do this while sitting comfortably at your computer as you read this:
1. Start by actively and emphatically drawing air into your lungs. Exhale simply by releasing it, rather than actively pushing it out. You can do both through your nose. Repeat five or six breaths.