He first arrived in Spain in 2002 as part of the Moroccan contingent for the
World University Cross Country Championships, which was being held in
Santiago de Compostela that year. However, he did not compete and instead deserted the team, using the opportunity to stay on in the country and train with other Moroccans in
Valencia. He later moved to
Lleida, working with coach Antonio Cánovas, and received citizenship in 2007 after five years of residency. His first major competition for Spain came the following year in the form of the
2008 Summer Olympics. He ran in the 10,000 m race and finished in 24th place, just behind compatriot
Carles Castillejo. He came fourth at the
2008 European Cross Country Championships at the end of the year, helping the Spanish men to the team title. He represented Spain twice at cross country in 2009, coming 30th at the
2009 IAAF World Cross Country Championships and fifth at the
2009 European Cross Country Championships, where Spain retained the team title. He also competed in the
2009 World Championships in Athletics, running in the
10,000 metres, but dropped out mid-race. He won his first track medal at the
2010 Ibero-American Championships, taking the
gold medal in the
5000 metres. At the
Great Manchester Run he duelled against
Haile Gebrselassie and ended up as runner-up some seven seconds behind the Ethiopian. Lamdassem was selected to run the 10,000 m at the
2010 European Athletics Championships in
Barcelona. After leading early on, he eventually slowed on the final lap and missed the medals with a fourth-place finish. He started his 2010/11 cross country season with a third place at the
Soria Cross Country in November. At the
2010 European Cross Country Championships he was the first runner to break from the front, although he was caught by
Serhiy Lebid and finished as the
silver medallist. Lamdassem also led the Spanish men to the bronze in the team competition. He competed at the
San Silvestre Vallecana on New Year's Eve and was leading ahead of favourite
Zersenay Tadese in the latter stages, but he took a wrong turn on the course, losing his leading margin and eventually finished as runner-up. A third-place finish at the 2011
Great Edinburgh Cross Country helped the European team to the title. He took the top honours at the
Cinque Mulini in February – a performance which lifted his club Bikila Toledo to third for that year's
European Cross Country Club Championships, which was held in conjunction with the race. He carried the hopes of the host nation at the
2011 IAAF World Cross Country Championships in
Punta Umbría and was the first European to finish, taking 16th place. He won the 2011
Cursa Bombers, although it was a Catalan-only race and his winning time was relatively slow. He missed the track season due to injury and returned in November, coming seventh at the
Cross de Atapuerca then second at the Soria race. At the
2011 European Cross Country Championships he was again the runner-up, this time to
Atelaw Yeshetela. He was the top European at the
Cross de Venta de Baños later that month, coming second to Kenya's
Philemon Kimeli. A third place at the
San Silvestre Vallecana closed his 2011 season. Lamdassem returned to the Edinburgh Cross Country in 2012 and won the long race, beating European champion Yeshetela. He won the European Club's Cross Country meet in
Castellón, leading Bikila Toledo to the title. He debuted over the
marathon distance at the
Lake Biwa Marathon but finished 23rd with a relatively slow time of 2:14:39 hours. Returning to shorter distances, he came second to
Kenenisa Bekele at the
Great Ireland Run and won the
Cursa Bombers in April. In June he was a silver medallist at the
European Cup 10000m and placed sixth in the event at the
2012 European Athletics Championships. He was selected to run the event for Spain at the
2012 London Olympics, but did not perform as well, coming in 23rd place in 28:49.85 minutes. In his first
half marathon in eight years, he came seventh at the
Great Scottish Run. A better outing came at the
Great South Run 10-miler, where he was runner-up, and near the end of the year he came sixth at the
2012 European Cross Country Championships. At the start of the 2013 cross country season he made the top two at the Great Edinburgh race and the European Clubs competition. ==Achievements==