Often times kids who play sports activities are categorized as bullying individuals when bullying happens. This is not to say that all sports players are bullies. I am just saying that often times those idnivduals that do bully others are or were involved in sports activities at some point in time.
Whether one plays sports has nothing to do with whether or not they are involved in bullying. Bullies are not necessarily the stronger. Truthfully, there are many times bullies are weak which is part of the reason they bully. Picking on someone else helps them to feel better abut themselves. Bullies are in every social group whether athletic or not.
It used to be a cliche, in Hollywood at least, that the jock was always the bully. They would always be the one to treat the nerds as lesser people. I don't think this is true anymore. With the internet, and cyber bullying, everybody is being hurtful to everyone else. No longer are we just blaming athletes.