By the conclusion of those Games, however, she had transformed herself from a top athlete to a Canadian icon.
Klassen, who announced her retirement in her native Winnipeg on Saturday, became the only Canadian athlete to win five medals in a single Olympics, winning one gold, two silver and two bronze.
Her performance was so impressive it prompted then International Olympic Committee president Jacques Rogge to proclaim Klassen as "the woman of the Games."
Klassen, 35, first came to world prominence in 2002, when she won an Olympic bronze medal in the 3,000 metres at the Salt Lake City Games.
A year later, she became the first female Canadian in 27 years to win the overall world title.
Klassen is tied with former teammate Clara Hughes for the most Olympic medals won (six) by a Canadian athlete.
Injuries hindered Klassen throughout her career.
Prior to the start of the 2003-04 season, Klassen sliced her forearm after a fall in training. The deep cut measured 10 centimetres and she also damaged 12 tendons in her forearm.
In 2008 she missed six months after having arthroscopic surgery on both knees.
While she continued to race up until 2013, Klassen would never regain her Olympic form.
Klassen hasn't raced the last two years. She suffered a concussion while inline skating in the summer of 2013.
She is the second Olympic great Speed Skating Canada has lost to retirement in the last two weeks.
Christine Nesbitt, the 2010 Olympic champion in the 1,000 metres, announced her retirement on June 4 in Calgary.
The London, Ont., native wrote a heartfelt, first-person retrospective piece for CBC Sports the same day, recalling a trio of cross-country races against a young rival named Laura Roberts that changed her life.
As part of Klassen's achievements at the 2006 Winter Olympics, a special 25 cent coin was created by the Royal Canadian Mint in celebration of her five medals in 2010, featuring the Canadian in a speed skating pose.
Three million of the 22 million coins were produced in colour.
All statistics compiled by Infostrada Sports.
Awards and honours- 2007 Female Athlete of the Year at the Canadian Sport Awards.
- Speed Skating Canada's Female Speed Skater of the Year in 2003, 2005, 2006, 2007.
- Canadian Press Female Athlete of the Year in 2005, 2007.
- 2006 Canadian Female Athlete of the Year.
- Canada's closing ceremony flag-bearer at 2006 Olympic Winter Games.
- 2006 Lou Marsh Athlete of the Year.