Education
Hardcastle finished second in the 800-metre freestyle at the British national championships in 1982, aged 13.
Hardcastle finished second in the 800-metre freestyle at the British national championships in 1982, aged 13.
She specialised in the 400- and 800-metre freestyle, and also competed in medley races. She retired from the sport in 1986 but returned in 1993, winning gold at the World Short Course Championships for the 800-metre freestyle in 1995 and reaching the final of the same event at the 1996 Summer Olympics. 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.
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.
At the 1996 Olympics in Atlanta she reached the final of the 800-metre freestyle, finishing eighth. Hardcastle retired permanently from competitive swimming after the 1996 Olympics, later moving to New Zealand to work as a swimming coach.