Lindsey Vonn turns 29

Lindsey Vonn :: Warwick Saint/SI

Vonn makes a snowball during a 2008 SI photo shoot. (Heinz Kluetmeier/SI)

Vonn stays warm by the fire during a 2008 SI photo shoot. (Heinz Kluetmeier/SI)

Vonn poses with Vern Troyer at the 2011 Cedars Sinai Sports Spectacular. (John Sciulli/Getty Images)

Vonn attends 2013 CFDA Fashion Awards in NYC. (Bryan Bedder/Getty Images)

Behind the scenes at Lindsey Vonn's 2009 SI Swimsuit shoot. (Tom Ryan/SI)

Vonn "Tebows" during the 2012 ESPY Awards in Los Angeles. (Kevin Winter/Getty Images)

Vonn appears during Tiger Jam 2012 at the Mandalay Bay in Las Vegas. (Ethan Miller/Getty Images)

Vonn poses on the set of her 2010 Got Milk? Mustache ad. (Christopher Polk/Getty Images)

Vonn trains with a physioball in June 2009. (Drew Gardner/SI)

Vonn poses in Austria during a 2009 SI photo shoot. (Drew Gardner/SI)

Vonn rehabs her knee in Vail earlier this year. (James Macari/SI)

Lindsey Vonn :: Warwick Saint/SI

SI proclaims Vonn to the best best American woman skiier ever in Jan. 2010. (Bob Martin/SI)

Vonn poses in the bathtub during a 2009 SI photo shoot. (Warwick Saint/SI)

Lindsey Vonn :: Warwick Saint/SI

Vonn celebrates her gold medal after winning Women's Downhill Final gold in Whistler during the 2010 Olympics. (Simon Bruty/SI)

Vonn continues her training by working on the hurdles in 2009. (Drew Gardner/SI)

Vonn and boyfriend Tiger Woods attend the 2013 Met Ball. (Stephen Lovekin/FilmMagic)

Lindsey Vonn :: Warwick Saint/SI

Vonn attends the 2013 Delete Blood Cancer Gala in NYC. (Dimitrios Kambouris/Getty Images)