Zemzem represented Ethiopia at the 2008 Summer Olympics in Beijing, and competed in the women's 3000 m steeplechase, along with her teammates Sofia Assefa and Mekdes Bekele.

She ran in the third heat of the competition, where she finished in fourth place and automatically advanced into the final, with a personal best time of 9:25.63.

[2] She bettered her performance in the final round, and set a national record, with a time of 9:17.85, just eight seconds faster than her own personal best, finishing only in seventh place.

[3] She returned to the global stage at the 2009 World Championships in Athletics and finished tenth in the steeplechase with a run of 9:22.64 minutes.

She did not compete in the 2010 and 2011 seasons and re-emerged in 2012 with a renewed focus as a long-distance road runner.