Steroid debate why steroids should not be in sports?

i am writing a debate on why steroids should not be used in sports. my proposition statement is "i negate the proposition that steroids should be used in sports." i need 3 contentions for my debate i only have one and its because steroids harm the body and have bad side effects. i cant think of any other contentions (reasons why steroids should not be in sports). please help!