Lars Boom

In December 2019, Boom announced that he was retiring from road racing after being unable to find a contract for 2020, due to his Roompot–Charles team folding at the end of the season.

In January 2018 Boom had a successful heart surgery to treat a cardiac arrhythmia. Boom returned to racing for the Paris–Nice in March.

In May 2018, Boom was expelled from the Tour of Norway for aggression against Belgian rider Preben Van Hecke. Video images showed some kind of incident where Van Hecke had to brake and Boom was upset about this. He overtook Van Hecke and punched him and attacked his helmet during the race. On 2 July, the UCI suspended him for a month, missing the Tour de France as a result.

After two seasons with Astana, Boom announced in August 2016 he would be joining LottoNL–Jumbo.

Subsequently, Boom announced that he would be leaving Belkin and joining Astana for the 2015 and 2016 seasons.

Coming into the Tour de France, Boom's notable results of the 2015 campaign were fourth in Paris–Roubaix and sixth in the Tour of Flanders. There was some controversy at the beginning of the Tour, as Boom's cortisol levels were too low in his blood per MPCC rules to participate in a cycling event, but the Astana management decided to field him anyway. Boom blamed his asthma inhaler for his low cortisol levels.

In 2014 Boom won the fifth stage of the Tour de France, a stage marked by difficulty due to wet conditions and significant sections of cobblestones. The stage was his first win of 2014. It was exactly nine years ago that a Dutch rider, Pieter Weening, won a Tour de France Stage.

Boom won the Dutch Cyclocross Championship for the sixth consecutive time in January 2012, extending his consecutive streak record.

Boom started the 2010 season by winning the Dutch national cyclocross championships. This was only his second and last cross of the season he rode. In the prologue of Paris–Nice he bested time-trial giants Jens Voigt, Levi Leipheimer, Alberto Contador and David Millar. During the winter of 2010–2011 Boom made a short return to cyclocross, he won the World Cup race in Zolder and won for the fifth consecutive time the Dutch national cyclocross championships. In 2011 he was again the fastest in a prologue of a World Tour event: the Critérium du Dauphiné. Later that year he won two stages and the general classification in the Tour of Britain.

In 2009 Boom won the Tour of Belgium after a strong performance uphill, and in the final Time Trial. In his first Vuelta a España, he was part of a break of 12 riders in the 15th stage. He rode away on the final climb and took the stage, making him the first Dutchman to win a stage in a Grand Tour since 2005.

Born in Vlijmen, Netherlands, Boom has also previously competed for Rabobank and their junior and continental teams over two spells with the team, as well as Astana. Boom won the cyclo-cross world championships in 2008. He has also been the Dutch national cyclo-cross champion in his discipline from 2001 to 2012 – junior cyclo-cross champion from 2002 to 2003, under-23 champion from 2004 to 2006, and the elite champion from 2007 to 2012.

During the 2008 road season, Boom continued his progression on the road despite a successful cyclocross season. On his third day of racing on the road, he won the third stage of the Tour de Bretagne in Fréhel. Boom also won the sixth stage time trial. Boom then dominated the oldest stage race in the Netherlands – the Olympia's Tour. After competing in two stage races in Spain in which he won the first and won three stages in the second, Boom returned to the Netherlands where he won the Dutch national road race championships for elite riders. He would win the national time trial title several weeks later after which he announced that he intended on switching focus from cyclo-cross to road racing after the 2008/09 cyclo-cross season.

For the 2006–2007 season, Boom asked and received special dispensation to ride the Dutch Elite Cyclo Cross championships and became Champion of the Netherlands. In addition to Boom's successes in cyclo-cross, he has achieved success on the road and has won several stage races such as the Tour de Bretagne. In September 2007, Boom became Under 23 World Time Trial champion beating Russian Mikhail Ignatiev. In November 2007, Boom won the Gerrit Schulte Trophy as the Dutch cyclist of the year for his two World Championship wins. In the 2007–2008 Cyclo-cross season, Boom won a World Cup event in Pijnacker, a Gazet van Antwerpen event in Loenhout and then became Dutch Elite National cyclo-cross champion for the second time. After that, he also won the World Cup races in Liévin and Hoogerheide. He went into the world championships in Treviso 2008 as big favourite and did not fail, he won the race and became the second rider after Radomír Šimůnek to win the world title in all categories (Junior, Espoir and Elite).

During the 2005–2006 cyclocross season, Boom who just turned 20 years of age, scored several wins including a win ahead of Sven Nys in the Grand Prix Sven Nys as well as the win in the Vlaamse Druivenveldrit Overijse after Bart Wellens was disqualified for having kicked a spectator. Boom was beaten by Zdeněk Štybar in a sprint for the Under 23 World Championships but returned a year later to dominate the race and to win the Under 23 World Champion jersey.

Lars Anthonius Johannes Boom (born 30 December 1985) is a professional cyclo-cross and mountain bike racing cyclist. He has also competed professionally in road racing, between 2004 and 2019.