Extreme Endurance Athlete
Think about what it takes to run a marathon. Months of training and preparation. Now imagine running a marathon every single day. That's what extreme athlete Diane VanDeren does to prepare for her races – unbelievable distances of 100 to 435 miles. She's teamed up with doctors at Mayo Clinic to help them learn more about what makes elite athletes able to accomplish such feats. Especially for an athlete like Diane who overcame a debilitating illness to become the world's most elite female endurance runner.