Born and raised in Sweden, Kristian played high school tennis in Idaho as an exchange student, winning the Idaho State 5A Championship title in 1990. This led to a 4-year collegiate career at Boise State University. Widen began his professional coaching career at BSU as an assistant and was a member of the Idaho Sneakers World Team Tennis team. He returned to Sweden in 1999 and spent a decade working as a head coach, private coach, club pro, team scout and travel coach for the National Swedish Tennis Federation. Kristian traveled and instructed elite players competing in the Australian Open Junior Grand Slam, the European Junior Championships and multiple International Tennis Federation (ITF) tournaments. Widen served as a travel coach for players competing at the Stockholm Open, Wimbledon and Stella Artois Championships. He eventually returned back to the US and to the Boise State Tennis Coaching Staff, serving as the Women’s Assistant Coach and then as the Men’s Head Coach until 2022.