Einar Uvsløkk made his debut on March 15, 2003 in Stryn with a 40th place in a Gundersen competition in the B-World Cup of Nordic Combined . In the following years he regularly competed in this competition series. In the 2006/07 season he won three races in Stryn and Kuusamo and ahead of the German Steffen Tepel and his compatriot Mikko Kokslien the overall ranking of the B World Cup.
In 2004 he started a total of four times in the Nordic Combined World Cup . However, he never reached the points there, his best result was a 38th place in Trondheim in December 2004.
Uvsløkk took part in the Nordic Junior World Ski Championships in 2004 in Stryn and in 2005 in Rovaniemi . In 2004 he won the gold medal in the team competition together with Kokslien, Jon-Richard Rundsveen and Petter Tande . In the individual competitions, fourth place in the Gundersen competition on the normal hill was also his best result in 2004.
Uvsløkk completed his last international competition on March 8, 2009 at a Continental Cup in Høydalsmo . He lives in his hometown Trondheim.