Estremera, a native of San Juan, Puerto Rico, was the 2007 IC4A University Division champion in cross country. He also garnered All-East honors three times and All-America East laurels twice as a harrier. On the track, Estremera became the first Great Dane to garner All-America honors in a distance event at the Division I level when he placed 11th overall, and eighth among Americans, in the 3,000-meter steeplechase at the 2009 NCAA Outdoor Track & Field Championship. He broke the school record in the event three times as a senior, setting the current standard of 8:48.72 in the prelims at NCAAs. A member of the Puerto Rico National Team, he was also a two-time America East champion and a member of UAlbany's IC4A indoor and outdoor championship teams.
Estremera earned a bachelor's degree in biology at UAlbany in 2009 and is currently pursuing his Ph.D. in linguistics. A teaching assistant for the Elementary Spanish course (ASPN 100) at UAlbany, Estremera continues to train for the Puerto Rico National Team and hopes to represent his native country as a steeplechaser at the 2012 Olympics in London.