Take a look at this profile of Bethany Sachtleben in the Washington City Paper:
Sachtleben was a homeschooled soccer player for most of the time she was growing up but then quit soccer. She then started running on her own to stay in shape and signed up for a marathon. Worried she wouldn't be able to finish, she ran 20 miles on a treadmill the day before the race ( her longest run before that was 8 miles). She never looked up a training plan online or even wore a watch in the race, but she ran the marathon in 3:08 and then walked on to George Mason.
Now 27, she recently was 2nd at the US 15k. She ran 2:31:20 at CIM (for 6th in December).
"I literally did not know running had workouts in it,” Sachtleben says on a recent afternoon, sitting just a few feet from the school’s indoor track. “I never watched track. I watched the Olympics, but I was like, ‘Oh, track’s boring. I don’t want to watch.’ So I never watched those events … I watched gymnastics, figure skating, all the fun sports.”