Hardcastle finished second in the 800-metre freestyle at the British national championships in 1982, aged 13. She was selected for the England team at the 1982 Commonwealth Games in Brisbane, where she reached the final of the 800-metre freestyle. In 1983 she won the bronze medal in the 800-metre freestyle at the European Championships, aged 14. At the 1984 Summer Olympics in Los Angeles, she became the youngest ever British woman to win an Olympic medal when she won silver in the 400-metre freestyle, aged 15 years, 3 months and 22 days. She also won bronze in the 800-metre freestyle, and finished ninth the 400-metre individual medley. Hardcastle won the silver medal in the 800-metre freestyle and finished sixth in the 400-metre freestyle at the 1985 European Championships. At the 1986 Commonwealth Games, she won gold medals in both the 400- and 800-metre freestyle. Her time of 8:24.77 in the 800-metre freestyle was the second-fastest ever recorded, 0.15 seconds outside the world record held by Tracey Wickham, and a new European record. Her time in the 400-metre freestyle was a Commonwealth Games record. She also won bronze in the 400-metre individual medley, and was a member of the team that won silver in the 4×200-metre freestyle relay. She won the bronze medal in the 400-metre freestyle at the 1986 World Championships. Hardcastle initially retired from competitive swimming in 1986 at the age of 17; in a 2012 interview she said that after years of training she had wanted to have a normal teenage life. After a spell working as a secretary at Ford, she decided to return to the sport in 1992 and resumed competing in 1993. Hardcastle was a member of the relay teams that won bronze in the 4×200-metre freestyle at the 1993 European Championships and silver at the 1994 Commonwealth Games, where she also won an individual bronze medal in the 400-metre freestyle. In 1995 she won the 800m freestyle gold medal and bronze in the 400m freestyle at the World Short Course Championships. At the 1996 Olympics in Atlanta she reached the final of the 800-metre freestyle, finishing eighth. At the ASA National British Championships she is a five times winner of the 400 metres freestyle in and four times winner of the 800 metres freestyle, in addition to being the champion over 400 metres medley in 1983 and 1986. Hardcastle retired permanently from competitive swimming after the 1996 Olympics, later moving to New Zealand to work as a swimming coach.
Personal life
Hardcastle was born in Chelmsford, Essex and attended Shoebury High School. Her mother, Ann Hardcastle, is a former swimming coach who taught several British elite swimmers including Mark Foster. Hardcastle married Lee Thomas in 1995; the couple have four children. Her daughter Eve Thomas is a current international swimmer representing New Zealand.
