Rock was born in Marshfield, Wisconsin, and grew up in Stratford, Wisconsin, where he graduated from high school in 2000. His high school career concluded at the 2000 Wisconsin State Championships, where he became the first athlete in meet history to win four individual titles at the same championships by winning the 110 m hurdles, 300 m hurdles, 200 m dash, and long jump. Despite this success, he was not a heavily recruited athlete.
Rock attended the University of Wisconsin–La Crosse, where he was a nine-time National Champion and a 17-time All-American. After finishing runner-up seven times between the 2001 and 2002 seasons, Rock hit his stride in 2003 and 2004, winning eight consecutive titles in the 400 m dash and 4x400m relay. Rock holds nine UW–LaCrosse records (four individual; five relays) and six WIAC records (three individual; three relays) and was twice named first-team Academic All-American by CoSIDA. In addition to these achievements, Rock also claimed the fastest 400 m time in Division III history, running a 44.66 at a USATF meet in Carson, California, thereby announcing his arrival onto the elite track scene. Rock turned professional soon after graduating from UW–La Crosse with a finance degree by signing a multi-year contract with Adidas.
Despite going through the rigors of the long NCAA college track season, Rock finished 6th in the 400 m at the 2004 Olympic Trials, earning him a spot in the relay pool for the Olympic Games in Athens, Greece. In the 2004 Olympic Games, Rock ran for the American 4x400m relay team in the qualifying heats, securing the team a place in the final. The relay took first two days later in the final, securing Rock a gold medal. In the 2005 World Championships in the Helsinki, he competed in 400m and won a silver medal, setting a new personal best of 44.35. Later in the meet, he led off the 4x400m relay team to yet another World Championship gold medal. Rock followed his 2005 season with a 2006 campaign highlighted by his 400 m win at the AT&T USA Outdoor Championships in Indianapolis. Coaches at Bethel University.