A record-setting American distance swimmer, Jensen won the silver medal at the 2004 Athens Olympics in the 1,500 meters in 14:45.29 and bronze at the 2008 Beijing Games in the 400-meter freestyle in 3:42.78. Both times remain American records. Jensen also won silver at the 2003 World Championships in the 800-meter free and silver in the 800- and 1,500-meter frees at the 2005 World Aquatics Championships. He attended Garces High for three years, then moved to Mission Viejo to compete with one of the top U.S swimming programs. Jensen set his first American record, in the 800 free, before his senior year at Mission Viejo High in 2002. In four years at USC, Jensen was a three-time NCAA champion and is still the Trojans' record-holder in the 500-yard, 1,000-yard and 1,650-yard freestyle races. Jensen is now a member of the U.S Navy SEALS after graduating at the top of his class at the U.S Navy SEALS training program in 2011.