Oh absolutely. Different muscle groups get trained for swimmers than for say, weightlifters or figure skaters. Also, muscle built in some sports also requires fat reserves, some does not. It's great people watching and trying to guess what sport someone does. Same with building characters in Poser. I have a few who are designed with 'wearing heavy plate armor several hours a day' in mind, and they need to be very different from 'spends hours sitting very, very still on rooftops or chairs' types.