The swimming pool is great from many things, such as taking a dip on a hot summer day.
Another thing it may help with is reducing back pain.
Swimming in water is a great resistance exercise with much less stress on the joints. There is less stress on the body due to buoyancy which will reduce the effects of gravity. This article suggest that the back stroke is one of the best to start out with because it puts you back in the least amount of hyper extension compared to other strokes. Swimming can help you get back to exercising with less stress than a treadmill or an exercise bike. If you are suffering come in to get your back check and see if swimming would be right for you.