Riggs attended Red Bank High School in Red Bank, Tennessee. He helped lead the team to an undefeated season, 15-0, and the school's first state championship in football during the 2000 season. Riggs also won the Tennessee Mr. Football trophy that season. He played in the 2002 U.S. Army All-American Bowl
Riggs was one of 2 different 1,000 plus yard rushers for Tennessee in 2004. He and Cedric Houston both had 1,000 plus yards that season. The first time in Tennessee football history to have multiple 1,000 yard rushers in a season.
Riggs was a preseason All-American in 2005 but he was injured toward the middle of his senior year and did not return to play for the Volunteers.
Riggs entered the 2006 NFL Draft, but was not selected, partly due to concerns about his injury status. After the draft, Riggs signed a free agent contract with the Miami Dolphins. He was released by the team on September 2, re-signed to the practice squad on September 3 and then released again on September 5. He spent the season out of football.