The 2019 Boston 2 Big Sur Challenge is now sold-out. Only the fittest (or craziest!) runners ever attempt back-to-back marathons…much less 3,000 miles apart! 2019 will mark the tenth presentation of the Boston 2 Big Sur Challenge and we will welcome 400 of the world’s fittest athletes to participate in two of the world’s greatest marathons. After a year with no official program sponsor, we are pleased to announce HOKA ONE ONE as the official Boston 2 Big Sur sponsor. All B2B participants will receive exclusive HOKA gear and other unique, quality items. Learn more about Boston 2 Big Sur.