Nikolov practiced many sports as a teenager, but decided to do orienteering at the age of 17. At his first World Championships in Switzerland in 2003 , he finished 12th and 15th. In the following years he stayed in the middle and back field at international championships, but was occasionally able to do other races, including the Tiomila 2005 his class prove. In 2007 he was among the top ten at the World Championships for the first time, in 2009 he was sixth in the sprint championship and sixth in the championship in the long distance in 2010. He finally won his first medal at the European Championships in Sweden in 2012 when he finished second behind the Swede Jonas Leandersson .
Nikolow ran internationally for the clubs Stora Tuna IK from Sweden, Halden SK from Norway and Kalevan Rasti from Finland. In 2010 he won the Jukola with Halden. In 2011 and 2012 he ran for Kalevan Rasti and won the Jukola again in 2012.
