Rika Bruins took up swimming at the age of seven and gained national attention in 1950, at the age of 16, by setting a record in the 200 metres breaststroke. Proving that this was no fluke, she won her first of three titles in that event at the Dutch National Championships the following year. She did not like to travel, however, and this hampered her performances internationally, and she was 10th at the 1952 Helsinki Olympics and sixth at the 1954 European Championships. In the latter year, however, she helped set a world record in the 4x100 metres medley relay and improved upon it in 1955. After this, however, she retired from competitive swimming and took up water polo instead.