Most top athletes have a fighter mentality and they often ignore pain in order to push to the end. But pushing to the end is not a good thing when you have a concussion. According to the CDC (Centers for Disease Control and Prevention), a concussion is “a type of traumatic brain injury, or TBI, caused by a bump, blow, or jolt to the head that can change the way your brain normally works.” A single concussion can cause long term damage to the brain so it's very important to protect against it. FITGuard helps determine if you are at risk of suffering a concussion after a hit so you can decide to stop and recover or continue. It's not commercially available yet but you can join its Beta-Testing program. If you're looking for something that's already proven, check out Reebok's Checklight Head Impact Indicator.