In 1989, her first year competing, Furtado won the US National Road Championship. She was then introduced to mountain biking, and 1990, again her first year competing, she won the cross-country event in (along with Ned Overend) the first official Mountain Bike World Championship, held in Durango, Colorado. In 1992 she won the downhill world championship. In 1996, Furtado won both the World Cup (her 3rd WC championship) and the NORBA (U.S. National race authority) cross-country championships. She also participated in the Atlanta Olympics. Unfortunately, though she was the overwhelming favorite to win, she suffered in the severe Atlanta sun and heat due to the as yet undetected Lupus in her system, and finished with an uncharacteristically slow 7th place. Soon after her Lupus was diagnosed, and again Furtado was forced into early retirement from her sport due to physical conditions. Her disease is currently under control and she still rides solo.
In 1998, the book "Rugged Racer" was written about Juliana's struggles and successes, overcoming injuries in her pursuit of her dream to compete in the Olympics. Despite a short MTB career of 6 years, Juliana held a Guinness World Record for most career 1st-place finishes in MTB (male or female), and at that time her career total wins even exceeded the combined total wins of the most successful man (Ned Overend) and next most successful woman.
She became the mother of a son in 2008, and is currently working again with the U.S. National ski team, as an advocate for retiring athletes.