On January 21, 2008, Mallory Weggemann received an epidural injection to help treat back pain; however by the time it was finished she was forever changed. Complications with the procedure left the college freshman paralyzed from the waist down.
Weggemann has been a competitive swimmer since the age of seven. After her injury at the age of 18, Weggemann chose to return to the pool. In April 2008, her older sister found an article in the local newspaper discussing the Paralympic Swimming Trials. The meet was being held at the University of Minnesota Aquatics Center in Minneapolis, Minnesota. Still coping with her new disability, Weggemann found one thing unchanged, her love for swimming.
While attending the meet as a spectator with her sister, she met several of the US National Team coaches as well as her current coach, Jim Anderson. The following Monday, Weggemann returned to the pool and has been swimming since. She touts her Paralympic trials experience as life changing. "I have always loved the sport but when this happened I thought my days of swimming were over and when I realized I could still do it, well I will never forget that moment."
Weggemann broke her first set of world records at the Can Am Speedo Para Swim Meet held in Edmonton, Alberta Canada in July 2009. Weggemann set world records in the 50m freestyle, 400m freestyle, and 100m butterfly.
At the 2009 Short Course IPC Swimming World Championships in Rio de Janeiro, Brazil, in November 2009, Weggemann broke six more world records (50m freestyle, 100m freestyle, 200m freestyle, 400m freestyle, 50m butterfly and 20 point 4x50m freestyle relay) and took home five gold medals.
In August 2010 at the Long Course IPC Swimming World Championships in Eindhoven, Netherlands, Weggemann proved herself again in the pool by taking home eight gold medals (50m freestyle, 100m freestyle, 400m freestyle, 100m breaststroke, 50m butterfly, 200m individual medley, 400m freestyle relay, 400m medley relay) and one silver (100m backstroke). Weggemann finished the meet with nine World Records. The IPC wrote the following regarding Weggemann's performance. "USA's Mallory Weggemann (S7) was the most successful athlete of these World Championships, winning eight gold medals and breaking nine world records".
Weggemann was ranked number one in the world in six of the seven paralympic events.
Weggemann is currently on leave from the University of Minnesota - School of Journalism until after the 2012 Paralympic Games in London, UK