Adrian Peterson's miraculous recovery after blowing out his knee last year has been well-documented.
Peterson is currently preparing for the Pro Bowl in Hawaii, and in an interview with NFL.com he credited his recovery to genetics.
"Look at my dad. And my mom's side, my aunts and uncles, they're all ripped," Peterson said. "At 50 years old, they've got six packs and eight packs."
That's why he doesn't want to compare his recovery to Washington quarterback Robert Griffin III's. He doesn't know the genetic background of other athletes that have suffered the same injury.