Before turning to cycling, Carpenter was a speed skater, one of many athletes who excelled in both sports. As a speed skater, she competed in the
1972 Winter Olympics, where she finished 7th in the 1500m. She was fourteen years old at the time, making her the youngest American female Winter Olympian. Carpenter-Phinney trained with Norwegian coach Finn Halvorsen as part of the US National speed skating team that competed in the 1972 Olympics. Other members of the team included
Anne Henning and
Sheila Young (Ochowicz). In 1976, she won the U.S. national overall outdoor title, but an injury prevented her from competing in the Olympics that year. After failing to make the Olympic team in 1976, Carpenter-Phinney began to focus on bicycle racing. Outside of skating, while a student at the
University of California, Berkeley, her athletic career centered on rowing. She was a member of Cal's varsity for two seasons. In 1979, her varsity team finished second nationally, and in 1980 she reached the top of the American collegiate rowing world with a national championship in the varsity four. == Cycling career ==