Pierce began her sporting career as a swimmer, breaking state and national records whilst still at high school.

She earned an athletic scholarship to Stanford University to compete for their NCAA Division 1 women's varsity swim team.

After graduating in 2006 with her Master's degree, she moved to Austria, where she lived and raced full-time on the World-Cup circuit in Europe from 2007-2013.

Amber became internationally recognized as a respected domestique in the pro peloton and helped her American compatriots earn Olympic berths whilst racing for the US National Team.

Upon returning to America in 2014, she continued racing internationally as a pro for both American and European UCI World Tour teams.