Dean Karnazes is the ultramarathon runner best known for redefining what the human body can endure. Often called one of the greatest endurance athletes of all time, he’s famous for running distances most people consider impossible—like 50 marathons in 50 states in 50 consecutive days, and running hundreds of miles nonstop without sleep.

He joins Jenni, live on stage at last weeks National Running Show in Birmingham to tell tales of running in the hottest and coldest places on earth - and even give tips to all those trying to improve!