Football is much beloved for both its violence and its grace, but it’s the former that often keeps fans glued to their seats. Unfortunately, violence has consequences, and in the case of football and other sports, concussions are one of them. There was a time when athletes were told to "shake it off," when they suffered a big hit, but some high-profile deaths and injuries have begun to change the way the sports world sees concussions. Neurosurgeon Sanjay Gupta explored the issue of concussions by joining the J.H. Rose High School football team in Greenville, North Carolina for its 2011 season. A documentary about his time there will premiere this Sunday at 8 p.m. on CNN. Host Frank Stasio talks to Gupta, CNN’s Chief Medical Correspondent, about "Big Hits, Broken Dreams."