Arndt won the national individual pursuit championship four times and Olympic bronze in the same competition. But a viral infection during the 2000 Summer Olympics – causing a disappointing outcome  – marked the turning in her career. In two years, she finished third in the Grande Boucle (sometimes referred to as the "women's Tour de France)" in 2003, won the Tour de l'Aude twice (2002 and 2003), and added a silver medal in the road time trial at the 2003 world championship in Hamilton, Ontario.