He played college football for the Oregon Ducks and was selected by the San Francisco 49ers in the second round of the 2012 NFL draft.

James attended Liberty-Eylau High School in Texarkana, Texas, where he played running back.

Against the Arizona Wildcats, James rushed for 126 yards, 2 touchdowns and surpassed LeGarrette Blount's single season scoring record.

Despite missing the first game of the 2010 season due to suspension, James managed to break the Pac-10 all-time sophomore single season rushing record and led the country in both rushing yards (1,682) and touchdowns (22), ultimately earning a trip to the annual Heisman Ceremony in New York as a finalist.

Following the 2010 season, James received the Doak Walker award, given to best running back in the country, and was recognized as a unanimous first-team All-American.

Nevertheless, James' season ended with disappointment when Auburn kicked a game-winning field goal as time expired for a 22–19 victory.

In the first game of the 2011 season against LSU, James became Oregon's career rushing leader, surpassing the mark previously set by Derek Loville.

After the game, it was announced that X-rays were negative for a break and that James had suffered a dislocated elbow but popped it back into place before leaving the field.

On January 2, 2012, James rushed for 159 yards on 25 carries with one touchdown to help Oregon beat Wisconsin 45–38 in the Rose Bowl.

[15] In an interview with John Canzano of The Oregonian, James said of former Oregon Running Back coach Garry Campbell, "He’s authentic.

Despite limited workouts with school's track team, he placed 5th in the 2010 Pac-10 championships at the 100 meters, posting a personal-best time of 10.50 seconds in the semifinals.

[27] Prior to the 2015 season, he informed the media that he preferred to be addressed as "LaMike", stating his friends, family and teammates have always called him that.

As of 2024, James owned three Killer Burger stores in the state of Oregon, one located in Beaverton, one in Lake Oswego, and the newest in the same city as his alma mater, Eugene.