DAYTON, Ohio - Breathing is so second nature that few of us stop to think about the effects it can have on our health.

Learning to breathe properly can have a profound influence on our state of mind, relieving stress and promoting a feeling of well-being. Other benefits include better circulation, lower blood pressure and increased energy.

The vast majority of people are shallow breathers, using only a fraction of their lung capacity. They barely take in enough oxygen to expand the rib cage and, without being aware, they may also periodically hold their breath, breathe unevenly or over-breathe when exercising. The result can lead to fatigue, headaches, dizziness, fuzzy thinking and, in extreme cases, fainting.

Deep abdominal breathing, on the other hand, uses the diaphragm, allowing more air into the lowest and largest part of the lungs. Breathing more slowly and deeply can actually increase exercise capacity. One way to practice deep breathing is to slowly and fully inhale through the nose, pause for a few seconds, and exhale fully through the mouth.

Have you ever experienced headaches when exercising? Exertional headache may arise as a result of straining or holding one's breath when exercising, especially if lifting heavier weights. Typically with this type of headache, the acute onset of severe throbbing pain, lasting from a few seconds to a few minutes, is followed by a dull ache lasting anywhere from four to six hours. Thereafter, the headache seems to recur with exertion.

Exercise-induced asthma (EIA) is a narrowing of the airways that causes breathing difficulties. It is theorized that EIA is due to the cooling and dehydration of the lungs that occurs during activity as more rapid breathing takes place.

Sudden sharp, intense pain under the lower edge of the rib cage is known as a side stitch. Such pain is caused by a muscle spasm of the diaphragm and usually happens during rigorous exercise, such as long distance running.