After the 2004 Olympics, she held the Olympic, Commonwealth and World Championship Pursuit titles, and the records for those events.
Ulmer was born in Auckland, where she studied at the Diocesan School for Girls. Her grandfather Ron Ulmer was a track cyclist for New Zealand at the 1938 British Empire Games. Her father Gary was a national road and track champion.
In 1994 she won the World Junior Championship and placed second at the 1994 Commonwealth Games in Canada with a time of 3 minutes 51 seconds.
At the 1996 Atlanta Olympics she was seventh after qualifying 6th with 3m 43s.
At the 1998 Commonwealth Games in Kuala Lumpur she won the gold medal with 3m 41.7s.
At the 2000 Sydney Olympics she qualified 4th with 3m 36.8s and came 4th after losing the ride off for third by 0.08 of a second.
At the 2002 Manchester Commonwealth Games she won the gold and set a games record of 3m 32.4s.
In May 2004 she won the World Championship in Melbourne and set a world record of 3m 30.6s in qualifying. At the Athens 2004 Olympics she broke the world record in qualifying with 3m 26.4s and took almost two seconds off that time to win the gold in the final with 3m 24.5s. Ulmer reduced the world record by six seconds. The silver and bronze medalists, Katie Mactier from Australia and Leontien Ziljaard-van Moorsel from the Netherlands, also went under the previous world record (3m 30.6s) in each of their three rides. They rode faster with each ride and rode 3m 27.6s and 3m 27.0s respectively in the finals.
In May 2010 at Aguascalientes, Mexico at an altitude of 1,870 metres (6,140 ft), American Sarah Hammer broke Ulmer's world record with a time of 3m 22.269s. As of September 2014 nine current world cycling records for distances of 4 km or less have been set at Aguascalientes.
The current world championship record of 3m 27.268s was set by fellow New Zealander, Alison Shanks in Melbourne in 2012.
Ulmer did well in points races, winning a junior world championship and placing 3rd and 4th at senior world championships. She placed 2nd and 5th (twice) at Commonwealth Games.
After the 2004 Olympics she switched to road racing. The Cycling Archives website includes results for her competing in road races in the US, France, Australia, Belgium and Germany from 1999 to 2006.
She trained at the velodrome in Te Awamutu. Her home town is Cambridge. In the 2005 New Year Honours, she was made an Officer of the New Zealand Order of Merit, for services to cycling.
She announced her retirement from cycling on 24 November 2007. She attended the 2008 Olympics as a mentor.
In 2011, she signed up as an 'ambassador' for the New Zealand Cycle Trail. Ulmer has two daughters.