According to the Aquatic Exercise Association, Aquatic fitness is defined as activities performed in the water that promote and enhance physical and mental fitness. Aquatic fitness is typically performed in a vertical position in shallow or deep water. There are numerous applications to appeal to a wide variety of participants.
Here's how it works... and why it works. Water buffers the body from gravity and makes a person virtually weightless when they are totally submerged. When a person's head is out of the water, he or she weighs approximately 10 percent of normal body weight. Therefore, exercising in the water offers protective cushioning that land-based exercise cannot.
Researchers tell us that exercise injury is usually related to impact. Every time a person's foot comes in contact with the floor, impact occurs. Because a person weighs so much less in the water, the impact on the body is reduced. Water has the same advantages to toning as it does in cushioning. In order to get muscles in shape or "toned," a person has to work against something. On land, a person fights gravity, but water limits the effect of gravity on the body.