In 2006, after having completed a few Olympic distance triathlons she entered and placed second in her age group at Ironman Switzerland, posting a sub-10 hour time.

She went on to compete at the 2006 Ironman World Championships in Hawai'i where she posted another sub-10 hour time and place third in her age group as an amateur.

[2] Steffen moved on to concentrate on bicycle racing as she was not enjoying the swim training and felt that her running was a competitive weakness.

Soon she was invited to join the Raleigh Lifeforce professional team alongside Nicole Cooke and Karin Thürig.

[7] In October 2012, she placed 2nd in the 2012 Ironman World Championship at Kona, Hawaii being narrowly passed by eventual winner Leanda Cave approx.