Bart Yasso, a runner for over 25 years and longtime Runner's World staffer and columnist, has completed in over 150 marathons around the world -- from Boston and New York to Antarctica, to Mount Kilimanjaro. He's one of the relatively few hardcore ultra-endurance runners to complete the Badwater -- a 146-mile running race considered the toughest run in the United States. Held in the 125-degree heat of July, Badwater starts in Death Valley, Calif. -- the lowest point in the U.S. -- and finishes on the top of Mount Whitney, at 14,496 feet the highest point in the 48 states. Yasso has been a race director for the past 25 years. These days, he oversees the Runner's World Half-Marathon, 5K and kids run, which hosts 2,500 runners in the half, 500 in the 5K and 1,000 children ages 5 thru 14 in the kids run. Less