Bumping your head while playing sports can cause serious harm. Scientists know that a hard hit to the head can lead to traumatic brain injury—bruising, bleeding, or other physical damage to the brain. But what sports caused most of these injuries? A recent study showed that for children and teens, contact sports were the biggest culprit. For adults, it was horseback riding. 

Phiroz Tarapore, a brain surgeon at the University of California, San Francisco, who led the study, says the difference is probably because “kids are more likely to be playing football than riding horses.” 

The researchers found that falling from a horse often causes more severe trauma than colliding with another athlete on the field. That’s likely because horseback riders are moving at greater speeds and are higher off the ground. But any head trauma can be dangerous, so it’s important to protect yourself no matter what sport you play. “Wear your helmet. No excuses!” says Tarapore.