Barrett Martineau began ski jumping and Nordic combined in 1998 and played these sports for 12 years, including four years in the national team of Canada. Among other things, he took part in four Junior World Championships in Nordic Combined, where he achieved 45th place in 2010 in Hinterzarten as the best individual . In the 2010 Olympic Games of Vancouver Martineau came as a fore to use and works as a trainer for these sports at the provincial level.
In 2010 Martineau switched to skeleton and made his debut in the international racing series of the FIBT in March 2012 with 11th place at the America's Cup in Lake Placid . In the following season he started again in this competition, which has now been renamed the North American Cup, and after finishing eighth in the first race in Park City, he was on the podium in all other races. He won all four races in Canada, namely on his home track in Calgary and in Whistler , and came out on top of Sean Greenwood and Patrick Rooney in the overall standings . At the Junior World Championships 2013 in Igls , he won the bronze medal behind Christopher Grotheer and Axel Jungk . In the winter of 2013/14 he was initially used again in the North American Cup and climbed to fourth place in Park City in the first five races. In the second half of the season he competed in the higher-class Intercontinental Cup and achieved sixth place in Whistler as the best place. He was seventh at the 2014 Junior World Championships in Winterberg .
At the beginning of the 2014/15 season, Barrett Martineau won his first medal with silver at the Canadian Championships and qualified for the Canadian World Cup team. He then made his debut in the World Cup in December 2014, finishing 16th in Lake Placid, which should remain his best result of the season. He finished 17th in the overall standings and 20th at the 2015 Skeleton World Championship .