[3] He closed his season with a run of 26:57.56 minutes in the 10,000 m at the Memorial Van Damme, setting an Ethiopian junior record.

[4] He entered the senior ranks in 2013 and promptly finished second at the Jan Meda International – Ethiopia's cross country championships.

[5] He was unable to repeat this form at the 2013 IAAF World Cross Country Championships, however, and in 69th place he was the last man of his team to finish.

At the 2016 Summer Olympics in Rio de Janeiro, Demelash competed in the Men's 10,000 metres, finishing in 4th place, only one hundredth of a second behind his teammate, Tamirat Tola.

Demelash made a strong surge in the last 10 metres, but Tola was able to reach the finish line quickly enough to elude him.