Firstly, they are professionals in their own fields. Even though they might have very good proportion for modeling, their bodies are trained for the best performance in sports but not for such purpose. For example, a professional swimmer has a sophisticated body silhouette. However, it is not to show off, but to swim faster. In addition, people who are interested in fashion care more about how the clothes look rather than who wears it. Therefore, modeling should be done by specialists, fashion models. Because they know how to pose to show the clothes best, and behave on occasions such as fashion show and photo shoot.
Secondly, not all the sports personalities have good appearance and body proportion. You may want to show that Sports players can turn into good models by mentioning Cristiano Ronaldo or David Beckham’s success in modeling. They are only successful because of their looks and fame. What about Leonel Messi? Does he have height or a very attractive face? Most of you will say no. So why should he be a model? Moreover, conflict between players may occur. Michael Neuer, a German goalkeeper, said that he doesn’t like those players who use their fame in soccer to join a clothing business. I personally agree with his opinion, and I would rather say famous sports personalities should not do modeling jobs but focus on what they do as specialists.
Finally, I will end by summarizing my points. First, there are specialists for modeling jobs, and therefore sports personalities are not necessary for it. Second, not all the personalities have good looks, and also conflict may occur among sports players. Therefore very lastly, famous sports personalities should focus on their own professions, no matter how much potential they have to be a good model.