Part 2 of the TED Radio Hour episode Champions.
About David Epstein's TEDTalk
Humans seem to have gotten faster, better and stronger in almost every way. Yet as sports journalist David Epstein points out, many factors are at play when we shatter athletic records.
About David Epstein
David Epstein writes about the science of sports from performance-enhancing drugs to the lucky genetics that separate the pros from the rest of us. A science writer and longtime contributor to Sports Illustrated, he's helped break stories on steroids in baseball, fraudulently marketed health remedies, and big-money irregularities in "amateur" college football.