Lake played for the UCLA Bruins from 1985 through 1988. He finished his college career with 45.5 tackles for loss and 25.5 sacks. Those totals, as of the 2009 season, are 1st and 4th in UCLA football history.
As a defensive back, Lake played 12 seasons in the NFL from 1989 to 2001 for the Pittsburgh Steelers, Jacksonville Jaguars, and Baltimore Ravens. As a rookie, Lake started 15 of 16 games and led the Steelers with 5 fumble recoveries. He was a 5-time Pro Bowl selection. Over the course of his career he recorded 25 quarterback sacks, intercepted 16 passes, recovered 17 fumbles, and scored 5 defensive touchdowns.
In 1997, Lake received a vote for MVP from Sports Illustrated writer Peter King, which created a situation where Barry Sanders and Brett Favre tied for the award that season.