According to a new study high-school male athletes are 1.4 times likelier to binge drink and 1.3 times likelier to fight.
The survey, conducted by Susan Connor, a researcher at Rainbow Babies and Children's Hospital in Cleveland, recruited 13,000 teens in America.
"The generalizations about how positive and safe sports are may not be warranted," the New York Post quoted her as saying.
On the other hand, boys who play team sports were found to be less prone to suffer from depression and to smoke cigarettes, researchers found.
And sports for girls are much more positive, as female teen athletes are less likely to fight, smoke, use pot or feel depressed.
The study will be released at the American Public Health Association's annual meeting.