Pushing the Limits: Skyrunning
If you think running a marathon is a feat in itself, imagine doing an ultra-marathon up a mountain. At "The Rut Mountain Race" in Big Sky, Montana, nearly 400 athletes from around the world gathered to compete across 31 miles. They cover more than 10,000 feet of elevation. The sport is known as "skyrunning." As part of the “CBS This Morning” series, “Pushing the Limits,” we take a look at the world’s elite athletes who are getting their high-altitude adrenaline rush.