Brenes won the gold medal at the 2012 IAAF World Indoor Championships in Istanbul, setting a new national and championship record. "Brenes improved his personal mark by approximately one second, something nobody expected on a championship, taking the gold medal", cited his personal trainer and motivator Andrés "Oro Fijo" Calderón. He has participated in major events like the 2007 World Championships in Athletics in Osaka, Japan, and achieved a 4th-place finish at the 2008 IAAF World Indoor Championships in Valencia, Spain. He also finished in 3rd place at the 2008 ÅF Golden League meet in Oslo, Norway.