Javier has competed in five Paralympics winning a total of seven gold and two silver medals. His first games were in front of his home crowd in Barcelona at the 1992 Summer Paralympics where he won gold in each of his four events, 800m, 1500m, 5000m and 10000m. He added a further two gold medals in Atlanta in 1996 in the 5000m and marathon but missed out on a medal in the 1500m. In 2000 he fell a little short of defending both titles when Robert De Friese Evans ran a world record to beat him in the 5000m but did defend his marathon gold. 2004 saw him compete in just the 5000m gaining his second consecutive silver medal in the event. His fifth games in Beijing in 2008 Summer Paralympics were the first time he failed to medal after finishing eleventh in the marathon.