Wisconsin's American Birkebeiner is like the Ironman of Nordic skiing: top pros from all over the world show up in droves. Which is why it was such a surprise when 27-year-old Matt Liebsch won it in 2009—he was the first American to clinch the full-length course in 17 years. Liebsch is an electrical engineer turned full-time salesman at a local gear shop and a father of two. That's not all: in 2009, he won the 58K Vasaloppet USA, an esteemed Minnesota race, and in Feb­ruary he repeated the win.

HIS SECRET: "Cross-country skiing is all about efficiency. That and a good babysitter. I get up at 5:30 or 6 a couple of mornings a week to ski uphill before the kids are awake. Last winter, when my daughter was smaller, I skied with her in a backpack. She was 20 pounds and felt like a heavy biathlon gun. I used to be able to keep a food journal, do body-fat testing, and pick what I ate carefully. But now that I'm on my feet working for six hours at a stretch, the first piece of food that lands in front of me, like a candy bar, I shove in my face. After ski season, I get fat. By May I'm tired of being fat and start training again for next year. Is there anything I miss? It would be nice to take a family trip other than a race weekend, which I don't think my wife and kids consider a vacation."

ON MATT: Dennis Tee shirt by Marc by Marc Jacobs ($78; marcjacobs.com); Rugger lightweight nylon bomber jacket by Gant ($185; gant.com); Authentic Army parachute pants by Polo Ralph Lauren ($145; ralphlauren.com); Vintage leather belt by Gap ($30; gap.com); Adidas Nizza Hi shoes ($85; shopadidas.com)