The researchers were inspired by working with ultramarathoners, who can be sidelined by blisters despite years of training. These runners competed in the 2007 Badwater Ultramarathon in Death Valley, Calif. Chris Carlson/AP hide caption

toggle caption
Chris Carlson/AP

Izaic Yorks, a senior at the University of Washington, recently ran a mile in 3:53 — the fastest mile of any American collegiate athlete. Here, he competes on Feb. 27 in Seattle. Stephen Brashear/Red Box Pictures hide caption

toggle caption
Stephen Brashear/Red Box Pictures

Why Fastest U.S. College Mile Runner Won't Be Vying To Be NCAA Champ

  • Download
  • <iframe src="https://www.npr.org/player/embed/470084460/470120014" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Haneen Radi, an Arab Israeli, wants to organize a marathon for her town of Tira, but was told the run couldn't include women. When she insisted, she received threats, and the back window of her car was shot out. Emily Harris/NPR hide caption

toggle caption
Emily Harris/NPR

Trying To Organize A Marathon, An Arab-Israeli Woman Runs Into Opposition

  • Download
  • <iframe src="https://www.npr.org/player/embed/408914842/409421449" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

From Skid Row To Rome: The Story Of An Unusual Running Club

  • Download
  • <iframe src="https://www.npr.org/player/embed/394035236/394217024" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

British Runner Leaps Feet-First Into Marriage

  • Download
  • <iframe src="https://www.npr.org/player/embed/370264872/370264873" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

English athlete Roger Bannister among a crowd at Oxford after becoming the first person in the world to run a mile in under 4 minutes (3:59.4). Norman Potter/Getty Images hide caption

toggle caption
Norman Potter/Getty Images

Carol Downing is still haunted by memories of last year's marathon. But she's excited about reuniting with other survivors. Michael Dwyer/AP hide caption

toggle caption
Michael Dwyer/AP

Despite Worries, Boston Survivor Heads Back To The Start Line

  • Download
  • <iframe src="https://www.npr.org/player/embed/302711747/303391677" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

Runners train in Ngong, Kenya, in 2012. The country has produced the world's best distance runners for decades, and most belong to the Kalenjin people. Michael Steele/Getty Images hide caption

toggle caption
Michael Steele/Getty Images

How One Kenyan Tribe Produces The World's Best Runners

  • Download
  • <iframe src="https://www.npr.org/player/embed/241895965/242412313" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript