"Running on a 2,000-year-old wall was more like navigating an obstacle course than competing in a marathon. During The Great Wall Marathon last year, we had to scramble on all fours where the wall was crumbling and scurry up endless stairs that took us high above tree line. I didn't want to get sunstroke in the 90-degree (32-degree Celsius) heat, so I ran with an umbrella, which flabbergasted the German, French, and Belgian racers. They thought I was just another lazy American, until I finished first in the Half."

After running the New York and Boston marathons and South Africa's 55-mile (89-kilometer) Comrades Marathon, New York City-based Cerfolio took on The Great Wall Marathon. A growing trend, international races are a great way to combine world travel with endurance sports. Next for Cerfolio is a jungle dash in Costa Rica.