He started out in 1993 riding Mountain Bike with the Alkon-Bike Romanes Team, from 2005 he also started riding road bike. As an amateur, Zugasti won amongst other competitions, the 2006 Catalan Road Championship, the 2006 Grand Classics and in 2007 Ranking in the Catalan Cycling Federation, all this with the Saunier Duval-Moncada Team. From 2008 with Azysa Team he won both the Tour of Cantabria and Tour of Salamanca; in 2009 the Tour of Castellón, Tour of Ávila, Tour of Sevilla and Silver Medal in the Spanish Road Cycling Championship which he did in Cantabria in the amateur elite category. These victories took him to be number one in the Spanish Federation Ranking. In 2011 as amateur he formed part of the team Vitaldent Val D´Aran, although he road some events on load to the team MMR-Spiuk. During the year his most important wins.