In October 1989, she was invited by Emilia Boneva to join the national rhythmic gymnastics team of Spain, of which she would be a part until 1992.

She was a substitute gymnast for the team at most competitions during that time, although she participated in some exhibitions in Spanish cities during the preseason and competed in international tournaments such as Karlsruhe.

The starting team that year was Beatriz Barral, Lorea Elso, Teresa Fuster, Montserrat Martín, Arancha Marty and Vanesa Muñiz, with Marta Aberturas and Gemma Royo as substitutes.

Their ribbon exercise used "Tango Jalousie", composed by Jacob Gade, for the music, while their mixed-apparatus one used the song "Campanas" by Víctor Bombi.

Prior to the World Cup, they won gold at the Karlsruhe tournament (ahead of the USSR and Bulgaria) and three bronzes at the Gymnastic Masters in Stuttgart, both in Germany.

[5] On October 12 of that year, the Spanish group won the gold medal in the all-around of the World Championship in Athens.

Alonso won these medals together with Lorea Elso, Bito Fuster, Isabel Gómez, Montse Martín and Gemma Royo, with Cristina Chapuli and Marta Aberturas as the group's substitutes.

[16][17] After her retirement, she began to teach physical condition, aerobics, ballroom dancing and rhythmic gymnastics in the town of Cervera de Pisuerga, where she lives with her family.