Travis Kauffman responds to questions during a news conference Thursday about his encounter with a mountain lion while running a trail just west of Fort Collins, Colo., this month. David Zalubowski/AP hide caption
running
Man Kaur of India celebrates after competing in the 100-meter sprint in the 100+ age category at the World Masters Games in Auckland, New Zealand, in April 2017. Michael Bradley/AFP/Getty Images hide caption
The Boerne Race is 0.5k long, and begins and ends with a glass of beer. Josiah Mackenzie/Flickr hide caption
Desiree Linden wins the women's division of the Boston Marathon on Monday. She is the first American woman to win the race since 1985. Charles Krupa/AP hide caption
Man Kaur of India celebrates after competing in the 100-meter sprint in the 100+ age category at the World Masters Games in Auckland, New Zealand, in April. Michael Bradley/AFP/Getty Images hide caption
Runners in the Gerrymander 5K will trace the boundary of two congressional districts that split Asheville, N.C. Ken Lane/Flickr hide caption
David Torrence, seen here during the 2014 Penn Relays at Franklin Field in Philadelphia, has died in Scottsdale, Ariz. Icon Sports Wire/Corbis via Getty Images hide caption
An African cheetah (acinonyx jubatus lanea) at Inverdoorn Game Reservein South Africa. Thierry Falise/LightRocket via Getty Images hide caption
Researchers had participants wear the fitness trackers while walking or running on a treadmill and while riding an exercise bike to determine how well the trackers measured heart rate and energy expenditure. Paul Sakuma/Courtesy of Stanford University School of Medicine hide caption
Fitness Trackers: Good at Measuring Heart Rate, Not So Good At Measuring Calories
Runners assemble at the starting line of the third annual Qingyuan marathon. Rob Schmitz/NPR hide caption
In Fast-Paced China, Marathon Craze Is Off And Running (Despite A Clumsy Start)
The laces on the left are tied in a strong knot that lies horizontally. The laces on the right are tied in a knot that makes the bow lie vertically and which, according to new research, can come untied more easily. Meredith Rizzo/NPR hide caption
Dr. Tonatiuh Barrientos Gutierrez, an epidemiologist in Mexico City, jogs near his home in the southern part of the capital. He says it's hard to run on the city's streets. Meghan Dhaliwal/for NPR hide caption
In Diabetes Fight, Lifestyle Changes Prove Hard To Come By In Mexico
Interval training includes bursts of high-intensity efforts sandwiched by periods of less activity. Jonathan Cohen/Flickr hide caption
Does 1-Minute Interval Training Work? We Ask The Guy Who Tested It
Jolly old Santa himself. Unpictured: the sweat, pain and — possibly? — tears that went into tracing his form on the map. Owen Delaney/Courtesy of Strava hide caption
The runners in Project Kirotshe take off through forested mountains. For participating in the club, they each get a stipend to pay school fees. Daniel Socha for NPR hide caption
Researchers have long known that exercise is good for the brain. An enzyme produced by muscles might help explain why. Monalyn Gracia/Corbis/VCG/Getty Images hide caption
A Protein That Moves From Muscle To Brain May Tie Exercise To Memory
Ida Keeling does pushups after breaking the world record for the 100-meter dash for centenarians at Penn Relays in Philadelphia on Saturday. Courtesy of Penn Relays hide caption
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
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
Why Fastest U.S. College Mile Runner Won't Be Vying To Be NCAA Champ
Gunhild Swanson, 70, clocked 29:59:54 in the Western States Endurance Run on Sunday. Screenshot from USLTV.com hide caption
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
Trying To Organize A Marathon, An Arab-Israeli Woman Runs Into Opposition
India's new wave of runners is ready to race. This crowd took off at the Airtel Delhi Half Marathon on Nov. 23. Zheng Huansong/Xinhua /Landov hide caption
In an image from video of the men's event at the Beer Mile World Championships, competitors are seen poised to open their beers, which they'll guzzle before taking off on their first of four laps. Flocast hide caption