Research shows that physical activity while immersed up to your neck in water is just what you need for physical fitness, rapid healing, pain management, and more. The latest information and research on the physiological changes that occur when you engage in physical activity while immersed in water is supported in an article written by Bruce E. Becker, MD titled “Considering the Biologic Aspects of Water.” Dr. Becker has researched, published, and taught extensively on aquatics. Research shows that water is the oldest rehabilitation modality known to mankind. Few understand the magnitude, variety, and rapidity of its healing properties. Much research over the centuries confirms these properties, and recent research adds further understanding. For example, physical activity within the aquatic environment while immersed to the neck produces physiologic changes that accelerate the removal of metabolic waste, improve cardiac function, lower blood pressure, and assist the body in healing tissue. The Circulatory System Immediately after a person is immersed, water begins to exert pressure on the body. This aids the circulatory system. For example, central venous pressure rises with immersion to the chest and increases until the body is completely immersed. Cardiac volume increases by nearly one-third with immersion to the neck. Since the ultimate purpose of the heart is to pump blood, its measure of performance is the amount of blood pumped per unit of time. This is called “cardiac output” and submersion in water to the neck increases cardiac output 32 percent at rest. Research shows structured deep-water exercise is the most ideal, aerobically efficient cardiovascular conditioning medium available. The Pulmonary System Like the circulatory system, the pulmonary system experiences profoundly positive effects by immersion of the body to the thorax. Part of the effect is due to the shifting of blood into the chest cavity, and part is due to compression of the chest wall. The combined effect creates a positive alteration of pulmonary function, increasing the work of breathing and changing respiratory dynamics. In fact, expiratory reserve volumes decrease by 75 percent at neck immersion, with vital capacity decreasing only slightly. The combined effects of these changes increase the total work of breathing by 60 percent. Thus, for an athlete accustomed to land-based exercise, water-based exercise offers a significant workload challenge to the respiratory apparatus. When water-training time is sufficient, this challenge can markedly improve the respiratory system’s efficiency. Click here for page two