She grew up in Soest, and later moved to France with her parents. In 2009, she moved to Eindhoven to train with Jeanet Mulder, after she had qualified for the 2010 European Aquatics Championships she changed coach to Jacco Verhaeren. As of 2014 she is coached by Philippe Lucas in Narbonne and Marcel Wouda in Eindhoven.[1][2] She is noted for her versatility, and focuses on distance freestyle events.[3] In a country known for its sprinters, she is the only elite distance swimmer.[4] She has won several medals at European and world championships, both in open water and pool events.
The 2012 Olympics in London were Van Rouwendaal's first Olympics. She competed individually in the 100 m backstroke and 200 m backstroke but due to a shoulder injury she did not make the finals. In the 200 meter backstroke event she finished 11th in the semifinals. In the 4 × 100 m medley relay she did swim the final, finishing 6th with the Dutch team. Van Rouwendaal (swimming the backstroke lead-off leg) and her teammates Moniek Nijhuis (breaststroke), Inge Dekker (butterfly), and Ranomi Kromowidjojo (freestyle) broke the Dutch record in this event.[7]
At the 2015 World Aquatics Championships in Kazan, Russia, Van Rouwendaal again competed both in the open water and pool events. In the open water events she won two silver medals. In the individual 10 km she finished 2.4 seconds behind Aurélie Muller of France for second place. By finishing in the top 10, she qualified for the 10 km marathon event at the 2016 Olympics in Rio de Janeiro. In the 5 km team time trial she and her teammates Marcel Schouten and Ferry Weertman finished in tied second place. She also finished 4th in the individual 5 km. In the pool, Van Rouwendaal won the silver medal in the 400 meter freestyle behind defending champion and world record holder Katie Ledecky, who had dominated this event since 2013. In this race she broke the Dutch record with a time of 4:03.02. In the heats of the 800 m freestyle, she also broke her own national record.[12] She broke her record again in the final but finished in 8th place. In the 1500 m freestyle she finished 6th.
2016 European Open Water Championships
At the 10 km event at the European Open Water Championships in Hoorn, the Netherlands, Van Rouwendaal missed a turn near the finish while in leading position. She ended up finishing 4th. Two days later she won a bronze medal in the 5 km event.[13]
2016 Summer Olympics
At the 2016 Summer Olympics in Rio de Janeiro, Van Rouwendaal missed the final of the 400 m freestyle, finishing 19th in the heats. She subsequently pulled out of the 800 m freestyle, and later won the gold medal in the 10 km marathon at Fort Copacabana in 1:56:32.1. After 6 km she broke away from the field, and finished 17 seconds ahead of silver medalist Rachele Bruni.[14]