In 1966 she participated for the first time in an international competition. She won 5 medals in the Stoke Mandeville Games that year, and in 1968 won 4 medals and gained a world record during the 1968 Summer Paralympics. Anlen continued to excel, winning seven medals in the 1971 Stoke Mandeville Games, 5 medals in the 1972 Summer Paralympics, and 4 medals in the 1976 Summer Paralympics. Over the years she won 13 paralympic medals and held three world records.