Duggan turned professional in 2005 with Teachers Insurance and Annuity Association, USA–CREF, and after six years with the squad, Duggan left for Liquigas–Cannondale in 2011. In 2013, Duggan competed with Saxo–Tinkoff. In 2006, he co-founded the Just Go Harder Foundation with fellow cyclist Ian MacGregor.
Born in Boulder, Colorado, Duggan skied competitively in high school, and became involved in cycling to maintain conditioning during the off season.
He excelled in cycling, and after graduation pursued it professionally. Duggan"s first national championship experience came in 2003 when he placed second in the National Under-23 Time Trial Championships.
In 2004, Duggan placed second in the National Under-23 Time Trial Championships and third in the National Under-23 Road Race Championships. Duggan turned professional with Teachers Insurance and Annuity Association, USA–CREF the following year.
Following a six year stint with Teachers Insurance and Annuity Association, USA–CREF, Duggan signed with Liquigas–Cannondale for the 2011 and 2012 seasons.
Duggan left Liquigas–Cannondale at the end of the 2012 season, and was scheduled to join SpiderTech–C10 for the 2013 season. However, the team was disbanded prior to the end of 2012, and Duggan was freed from his original contract. He later signed for Saxo–Tinkoff in November 2012, on a one-year contract.
In January 2013, he fractured his collarbone while negotiating a roundabout in Stage 3 of the Tour Down Under.
Following the 2013 season, Duggan retired from professional cycling. Personal life
In 2006, Duggan and Ian MacGregor founded the Just Go Harder Foundation.
The foundation"s aim is to create cycling and skiing scholarships for underprivileged children.