As a rookie linebacker for the San Francisco 49ers in 2014, Chris Borland registered 107 tackles, even though he didn't start until Week 7. He was even NFL Rookie of the Week that year. With a seemingly long and successful career in the league in front of him, Borland retired after his rookie season over concerns about long-term brain trauma. He joins John & Marcia discuss why he stepped away from football, plus his-post NFL life of preaching the benefits of meditation and his internship with former president Jimmy Carter's foundation.