In recent years, the sliding community — made up of skeleton, bobsleigh, and luge athletes — has experienced a spate of brain injury-related tragedy. At first glance, the reason why seems obvious: Sleds regularly reach speeds that top 90 miles per hour and crashes are unfortunately common.

But there is growing research that shows it might be the act of sledding itself that is the main driver of brain injury. With every run, athletes are exposed to immense force and vibration, causing micro-concussions that can add up to major damage. Those concussions are mild enough that they can go undiagnosed. But among sledding athletes, the symptoms that indicate a micro-concussion — headaches, dizziness, etc. — are so common they have a special nickname: “sled head.”

There’s a lot science still doesn’t know about sled head, and about the brain in general. But from what we can tell, it’s pretty clear that sliding sports put the brain health of their athletes at risk.

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