I enjoy swimming, it's among the top public recreational activities and it keeps me in shape
I love to swim and its a low impact way to get some exercise. how long have you been swimming?
Since I was a young child. I swim for exercise, though many swim for recreation, sport, and even survival 
I love to watch competitive swimming, have you ever done that?
local, national, and international competitions, including every modern Summer Olympics.
Science.
Swimming relies on the nearly neutral buoyancy of the human body. On average, the body has a relative density of 0.98 compared to water, which causes the body to float. However, buoyancy varies on the basis of body composition, lung inflation, and the salinity of the water. Higher levels of body fat and saltier water both lower the relative density of the body and increase its buoyancy.
Since the human body is
Many swimmers swim for recreation, with swimming consistently ranking as one of the physical activities people are most likely to take part in. Recreational swimming can also be used for exercise, relaxation or rehabilitation. The support of the water, and the reduction in impact, make swimming accessible for people who are unable to undertake activities such as running.
Purpose Health.
Swimming is primarily a cardiovascular/aerobic exercise due to the long exercise time, requiring a constant oxygen supply to the muscles, except for short sprints where the muscles