It is obvious that swimming is good exercise but you may not be aware that it is an activity that can be done for a lifetime and that the benefits far outweigh the effort that it may take to get yourself into the pool.
People swim for many different reasons; some simply like the feeling of slicing through water or floating while others enjoy the benefit to their lungs and heart; or you may be simply looking for a way to beat the heat of summer. Whatever the reason, swimming works.
Regular swimming does great things like building muscle strength, endurance and promotes cardio vascular fitness. If you happen to be big into other sports swimming can be a cross training type of thing, using the pool as a warm up before you start your land sports or exercises. It is a good way to increase the heart rate and it stimulates muscle activity; both of which can be easily accomplished in the water. Swimming is also a great way to cool down after working out or participating in sports by gently moving the blood through the muscles and helping you to relax.
You can also burn around 3 calories per pound of your bodyweight per mile; so someone weighing 150 pounds can burn about 900 calories if they swim a mile in about 30 minutes. But, even if you are not doing it for the exercise swimming is a good form of meditation; relaxing and swimming with minimal effort while concentrating on nothing but your stroke rhythm can actually give you a sense of well being, so swim on!