Swimming develops almost all muscle groups. Some of them are given more load on some - less. All depends on your style, but be aware that after hanging out at the pool, no muscle is not left without a load.
Most are loaded back muscles, shoulders and triceps. When swimming the breaststroke leg muscles significantly involved, and while swimming butterfly (or a dolphin, as it is called) you nice strengthen the abdominal muscles.
Needless to say that visiting the pool 2-3 times a week, you will burn a significant amount of calories. Swimming is one of the most energy-intensive sports, so if you have a minor problem with being overweight, you will be useful to use the swimming pool.
For endurance training swimming is also good. Do not be discouraged if you can not swim at first considerable distances without rest. With each workout Overcome your distance will increase.
Swimming, you will strengthen not only the muscles, but also internal. To train the heart and respiratory system will also be an additional bonus of regular swimming.
During the warmer months is not necessarily to swim in the pool, for its water activities, you can use the rivers and lakes. And if you are not afraid of extreme sports, it is possible to do winter swimming and swim in colder water. However, for this you should not have contraindications and preferably familiar with the specialized literature.
However, if you want to achieve any significant results in swimming, it is worth remembering that it is necessary to limit the exercise in some other sports. First of all, at the same time difficult to combine a good run and good swimming. Of course, triathletes somehow miraculously involved in both these sports, but if you follow more closely their results, it will be clear that both in swimming and running outstanding results they have not obtained. The whole point here in the calf muscles, which run at a constant going gets tough, and vice versa for a good swim demand flexible.
Also, do not get involved in fitness equipment, so as not to clog myself muscle. At a minimum, you need to stretch after class power pool.