Running a marathon is no small feat — 26.2 grueling miles. Some are happy to have completed one while others get the "running bug" and continue to compete well into their  10th or 20th marathon. Marathoners are a small group, in fact, only 0.5 percent of the United States population has run a marathon — but one woman is in a league of her own.

41-year-old Annette Fredskov of Næstved, Demark completed 366 marathons in 365 days. One marathon, every day, for one year. As if that's not enough, on Sunday, July 15th, when Fredskov reached her last day, she ran TWO marathons in 10 hours and 44 minutes. That's 9,589.2 miles in one year — yea, I did the math.

What inspired Fredskov to complete this amazing challenge? A diagnosis.

Three years ago Fredskov was diagnosed with Multiple Sclerosis. "But rather than let that get her down, Fredskov decided to see if she could outrun the disease," writes The Copenhagen Post.

The Post reported:

"Three years ago, I was diagnosed with multiple sclerosis and today I have – without any medication – no problems or symptoms of MS. I believe that running marathons has played a large role in the fact that I am healthy today," Fredskov wrote on her website. "Two years ago, I thought the same thing most people think: 'Running a marathon isn't healthy. A marathon is damaging to  the body and it takes a long time to recover.' I have now changed my mind. Marathons are the best things that have happened for my body and soul."