He was described as "the most accomplished sprinter in IHSA history" and finished 3rd in the 2017 Stockholm Diamond League with a wind-aided 100 metres time of 9.89 seconds.

[3] Shields grew up in Chicago, Illinois, where he was a standout prep sprinter for Leo Catholic High School.

[5][2] Though his grade-point average was sufficient, Shields did not have the necessary ACT score to qualify for an NCAA Division I scholarship.

[6] Because of this, Shields competed for the Wayland Baptist Pioneers track and field team in college, an NAIA school.

[2][7] After 2008, Shields was training under the HAAG Atletiek [nl] club in the Netherlands.