Decades of medical research and dozens of clinical studies have shown that patients with heart disease and/or diabetes have heavy breathing at rest. (You may find over 15 such studies on my website.) Instead of breathing 6-7 L/min (the medical norm), they pant up to 15-18 L/min at rest.
Furthermore, numerous medical studies have clearly shown that development of diabetes and heart disease is based, on a cell level, on low body oxygen content. Tissue hypoxia is the cause of both conditions.
How can breathing relate to oxygenation of cells? What could be wrong with over-breathing (or hyperventilation)? What this has to do with exercise?
Firstly, the normal breathing pattern is diaphragmatic and it delivers almost maximum possible oxygen content for the arterial blood (approximately 98-99 percent). Meanwhile, deep or big breathing is accomplished by means of the thoracic or chest muscles. This is the case with heart disease and diabetes patients. As a result, lower divisions of our lungs do not receive new air supply with superior oxygen content. Consequently, oxygenation of the arterial blood is decreased.
In the second instance, CO2, the ingredient that we exhale away, is certainly a most potent known vasodilator. Hence, heavy breathing decreases blood availability to each vital organ of the body.
As a final point, carbon dioxide is definitely indispensable for detachment of O2 from red blood cells so that it can get to tissues (the Bohr effect).
As a result, heavy breathing leads go low oxygen content in cell and tissues. When we breathe more air at rest, we get less oxygen in body cells.
What about exercise and breathing during exercise? Levels of CO2 in the arterial blood remain about the same during exercise. This is because our breathing is mainly regulated by the CO2 drive, not oxygen. As a result, when we start to generate energy and CO2, our breathing becomes heavier. However, when we exercise with mouth breathing, our arterial CO2 is less. Nose breathing creates more resistance and leads to less ventilation, thus, rising arterial CO2 and improving oxygen transport.
An additional factor relates to nasal nitric oxide, another powerful chemical that relaxes and dilates blood vessels, and lowers heart rate. Mouth breathing prevents absorption of nasal nitric oxide leading to increased heart rates during exercise.
Over 180 Russian medical doctors have been taught the Buteyko breathing techniques to over 20,000 people with heart disease and diabetes. These doctors found that mouth breathing at exercise can easily lead to heart attacks in heart patients, while both heart patients and diabetics often experience dyspnea (shortness of breath). (Bear in mind that hundreds of people die from coronary artery spasms during exercise due to mouth breathing.)
They also discovered that nose breathing is totally safe, but requires lower intensity (e.g., walking) for those who are not fit and have less than 20 seconds for the body oxygen test.
As a result, all these Russian medical professionals teach their patients that all exercise and physical activity must be done with nose breathing only (in and out). This helps to adapt the respiratory center to higher CO2 and slow down breathing patterns for many hours after the exercise. As a result, patients have slower and lighter breathing, more oxygen in body cells, and less symptoms.
In addition, breathing exercises and lifestyle changes are very beneficial to improve body oxygen levels. Some state-of-the-art respiratory retraining programs include: Oxygen Remedy, Amazing DIY breathing device, the Buteyko therapy, and Frolov breathing device.
Frolov Breathing Device Overview and analysis of the breathing device used by more than 2,000,000 of people in Russia
Diabetes: Causes, Effects, Treatment (from NormalBreathing.com)
Nose Breathing Prevents Exercise-Induced Asthma
NormalBreathing.com has hundreds of medical quotes and references, graphs and charts, tables, analysis of numerous respiratory techniques, results of clinical trials with free breathing exercises, lifestyle modules and their manuals, techniques, and other resources to increase cell and body oxygen levels and improve health.