Alemu broke new ground in 2012. He started with a 3000m best of 7:48.04 minutes for a bronze medal at the 2012 Asian Indoor Athletics Championships. He failed to make it out of the heats of the event at the 2012 IAAF World Indoor Championships but won the men's title at the Asian Cross Country Championships a few weeks later. In May he set two new bests: 69:31 minutes for the half marathon and 27:56.20 minutes for the 10,000 metres at the FBK Games. He ended the track season with a personal best of 13:21.54 minutes for the 5000m. He began 2013 with a win at the World Military Cross Country Championships, but failed to finish at the 2013 IAAF World Cross Country Championships.