swimming does help quite a bit with developing good endurance, cardio and overall strength. Depending on what you do with swimming it is useful (especially upper body) because it works out just about everything. Yes taller swimmers do have the advantage because they can touch ppl out in a close call and they have more sweep, but the broad shoulders and relatively lean muscle is all from swimming. It is excellent at burning off fat and gaining muscle. I suggest also doing entire lengths of the pool underwater, this will help your breathing and greatly increase your endurance. Try treading water with a medicine ball/weights for leg strength or if your ambitious and have the pool to yourself throw a few weights to the bottom of the deep end and see how many you can bring up. This are fun little things to break up the laps when they get boring.