When the head of F.A.S.T. Performance Training in Hayward, Wis., Bill Pierce heard Tad Elliott pulled off a cross-Atlantic trip to win the American Birkebeiner last February, he knew he had to have him back in town. Matt Liebsch, one of the Midwest’s nordic heroes and 2009 Birkie champion, thought the same. In July, F.A.S.T. held its first “Train Like a Birkie Champion” “Live & Ski Like a Champion” Purpose: This camp designed for the...