Swimming in addition to the typical benefits of all sports, exercise activity without impacts, the great aerobic development and involvement of all major muscle groups. It also provides security and facilitates the practice to people who for various reasons can not other sports. In the cardiac-vascular system Swimming is aerobic sport par excellence, and continued moderate aerobic work is most suitable for the most important muscle in our body, the heart. The heart is aerobic exercise muscle gets stronger and lose the fat that surrounds it. With each beat becomes more powerful and can move more blood through the body. As a result there is a lower resting heart rate, improving the economy and efficiency of our hearts. For the same reason increases the caliber of the coronary arteries, causing many of the problems of the cardiovascular system. Thus helping the heart to be more effective in the transport and return of blood. Reduces blood pressure, so that the whole body gets away with it. In the respiratory system: With swimming strengthen all muscles, including those who are responsible for filling and emptying his lungs, making each breath we take in more air with less energy expenditure, making breathing more efficient, increasing oxygenation and reducing stress these respiratory muscles, this motivates a low respiratory rate. When we swim of front crawl and keep breathing oxygen debt produces a motivating the body to increase the density of red blood cells and their ability to carry oxygen. Increases the area of transmission of oxygen to the blood, this is caused by increased capillarization and a greater number of functioning alveoli. It increases our lung capacity and clean our lungs.