Most Helpful Guy
But you have to swim a lot to get that build. You also have to use different types of strokes and make sure you're in good form. Also, most professional swimmers train regularly at the gym and sometimes run too. My little bro was a swimmer and his schedule was basically swim, gym and jogging 5-6 days a week.
The best way to get a great bod is to combine weight training (and don't be afraid to lift heavy once you work up to it), cardio (swimming/running/etc) and to eat right. Eat healthy, clean food, lots of protein, healthy carbs and healthy fats.
Phelps looks the way he does because he's an Olympic athlete and trains his ass off. You're looking at years of rigorous training.