Brannen won silver medals in both the 2006 Commonwealth Games in the 1500m (3:39.20), and the Pan Am Games in 2015 (3:41.66). He is also a 6x National Champion in the 1500m, Olympic finalist in 2016 (10th), and placed 10th in the 2013 World Championship 1500m. On top of these achievements, Nate also was a semi-finalist in the 1500m at the 2005 & 2009 World Championships and the 2008 Olympics Games. Additionally, Nate held the 1000m and 2000m Canadian records until 2022.