He swam for the University of Virginia, where he was an 11-time All-American and two-time Atlantic Coast Conference (ACC) swimmer of the year.

At the 2003 Pan American Games, in Santo Domingo, Dominican Republic, he won two individual silver medals in the 400 and 1500 m freestyle.

Crippen represented the United States at the Pan Pacific Championships in 2006, where he earned a silver medal in the 10 km open water swim.

In 2007, he earned a gold medal in the 10 km distance event at the Pan American Games in Rio de Janeiro, Brazil.

Two years later, Crippen won a bronze medal in the 10 km open water race at the 2009 World Aquatics Championships.

[3] A year later, Crippen again won silver in the 10 km at the 2010 Pan Pacific Swimming Championships in Irvine, California.

A report released by FINA following Crippen's death called for an update in open water swimming safety regulations.

[6] The report concluded that Crippen may have died of a "cardiac abnormality" and "uncontrolled exercise-induced asthma in unfavourable race environmental conditions".