The 2003 season marked a breakthrough for Olmedo as he took fifth in the European Athletics Indoor Cup and won the 800 m bronze medal at the 2003 European Athletics U23 Championships. He was the runner-up in the Spanish national championships that year behind Antonio Manuel Reina, gaining himself qualification into the 2003 World Championships in Athletics. At his first World Championships he was fourth in his heat, running 1:47.98, but this was not enough to qualify. Olmedo reached the Olympic stage the following year but again finished fourth in his heat, being knocked out of the 2004 Athens Olympics.