Most American kids quit playing sports by age 11. That means a lot of kids are missing out on some of the huge benefits of sports, including spacial awareness, physical activity and team skills.

It involves the impact of a specific force to the chest at a specific moment in the cardiac cycle. One cardiologist told NPR that what happened to Hamlin was likely "a perfect storm of events."

Playing competitive youth soccer can cost families a small fortune, excluding kids who might excel at the sport. There are efforts around the country to get more kids in the game.

Youth soccer games seem to unleash the worst in adult behavior. Parents and coaches yell at refs, the players and each other. Adults' sideline behavior has resulted in a national referee shortage.

NPR's Scott Simon tells the story of young football players just 8 and 9 years old who decided to take a knee along with their coaches and what happened next.