Nova Zagora
In 2012, he became gold medalist in the marathon event at the Balkan Championship in Belgrade, Serbia. The same year, he took the bronze medal at the Balkan Mountain Running Champşonships on June 7 in Nova Zagora, Bulgaria. At the 2012 European Mountain Running Championships held on July 7 in Denizli, Turkey, Muslu won the silver medal after six-time gold medalist Ahmet Arslan.