Breaststroke emphasizes biceps brachii and chest and abdominal muscles, while freestyle pays more attention to leg and arm muscles, that is to say, breaststroke depends on trunk and freestyle depends on limbs.

I don't know if you are a man or a woman, but if you are a girl, you must think clearly. Swimming can significantly strengthen your muscles and make them bulge. A man's bulge is called strong, and a woman's bulge is called deformation.