For more than one hundred years, runners tried to break the four-minute mile. Many said it couldn't be done. It was considered the “Holy Grail” of track and field. In fact, doctors wrote articles in medical journals explaining why it was physically impossible for the human body to run a mile in less than four minutes.  

However, in May 1954, a British medical student named Roger Bannister ran the mile in 3:59.4. His amazing accomplishment made headlines around the world. Yet what happened afterwards is even more amazing. The four-minute mile was broken again the next month ... and then again ... and again. It has since been broken more than 700 times, sometimes by several people in the same race.