At the time, her sporting career was partly funded by the Richmondshire District Council, where she swam for Derwentside ASC in Consett, as well as Richmond Dales ASC and Durham Aquatics. Joanne’s international swimming debut was in 2003, at the World Swimming Championships in Barcelona.
In 2006, she competed at the Commonwealth Games, where she won a silver medal in the 400-metre freestyle event. Two years later, on the 11th of August 2008 whilst at the Olympics, Joanne secured a bronze medal at the 400 metre freestyle. On the 16th of March, 2009, Joanne showed the world of swimming exactly the level of talent she possessed. With a time of 4:00.66, she broke the previous world record in the 400-metre freestyle. In the process, she beat her British rival and the former reigning Olympic gold medallist, Rebecca Adlington, who had previously set the world record with a time of 4:00.89.
Within the same year, she earned a silver medal in the 400-metre freestyle, whilst competing at the 2009 World Aquatics Championships. Though she finished behind Pellegrini, Joanne once again finished ahead of her rival, Adlington. At the same competition, she claimed a bronze medal in the 4×200 metre freestyle relay and a silver medal in the 800-metre freestyle. In doing so, Joanne earned the most medals than any British swimmer has ever won, in a single world championship.
Prior to retiring in 2012, Joanne competed at the London 2012 Olympics. Despite finishing 7th in the 400 metre freestyle heat with a time of 4:11.50, she was a part of the British team that finished 5th in the 4×200 metre freestyle relay. Joanne’s legacy as a top-level swimmer positioned Great Britain as a leading country of competitive swimmers.
Joanne is now a celebrated motivational speaker, and highly sought after keynote speaker. She features at events nationwide, sharing her extensive knowledge of not just swimming, but competing at peak performance. Audiences who witness Joanne speak are inspired to push their own capabilities, as she has done.