 Leading is priceless precisely because it's something you do. The NFL Players Association's medical director, Dr. Tom Mayer, is the man behind the league's concussion guidelines program, a game changer in sports medicine since 2011. Boston University professor Andrea Kramer invited him to speak to her journalism class about his upcoming book based on what he's learned from his diverse experiences as a medical emergency responder. I had several different players come to me and say, Doc, you know, you certainly saved my career because I wouldn't have reported a concussion and no one else would have either and I would have just kept playing and gotten hurt worse. Even the Super Bowl is fair game to these protocols. Any NFL player diagnosed with a concussion cannot return to a game until they pass the return to participation protocol which takes players nine days on average. Prior to the changes that we made, it was, what do you think is going to happen? These are big men. They run into each other. They're going to bang head. It's going to happen. And the changing culture is realizing it doesn't have to be that way. Mayer also led an emergency response team through the war in Ukraine, treating almost 350 displaced Ukrainians. Treating NFL players is part of his passion to help others, something he shared with students is a deep joy of his, a concept from his upcoming book. My obligation I think is to help all of them, no matter how long in the league, no matter whether they're a starter or not, no matter whether they sell, you know, 100,000 jerseys to figure out what's next, what's my deep joy, what is it that I want to do in the career, the life that I'm going to have long after football is gone. Dr. Tom Mayer's upcoming book about leadership is worthless, but Leading is Priceless is set to release May 7th. It draws on his experiences leading crisis teams through emergencies. Reporting for BU TV, I'm Chloe Adams.