Sian began triathlon at the age of just seven and has won medals at European junior and U23 level. She is currently based at Leeds Triathlon Performance Centre.
Sian has won silver at the Nanjing Youth Olympic Games (2014) as well as ETU U23 Mixed Relay gold (2017) and several ETU U23 and Elite Women podium finishes, including bronze at the Kecskemét ETU Sprint Triathlon European Cup.
Sian competed in and won her first ever multisport event aged seven. It was an Aquathlon event in Coventry and she has been winning races ever since. As a former English Schools 1500m Champion and National 1500m Champion, it is no surprise that Sian’s strongest event in triathlon is the run. She also represented England Junior girls at cross country in 2011 - her first international vest. She has been part of the Dame Kelly Holmes’ 'On Camp with Kelly' programme for talented middle-distance athletes (Non Stanford has also been part of this).
Her first international triathlon was in 2013. She helped Great Britain to win the European Junior Mixed Relay in that year as well as competing in the ITU World Championships in Hyde Park, London.
In 2014, aged 17, she won a silver medal competing for Team Europe in the Mixed Team Relay event at the Nanjing Youth Olympic Games in China. She also finished 8th in the individual event, representing Team GB. She has also won medals in European Cup and Championship events.
At the age of 18, Sian was diagnosed with Crohn’s disease. She has continued to deliver high class results despite a disease that can, at times, be debilitating.
Her full return to the sport was in 2017 where she recorded two successive podiums at the Velence ETU Triathlon U23 European Championships, winning and individual bronze and a Mixed Relay gold. She finished the year with a 9th place finish in the U23 ITU World Triathlon Grand Final Rotterdam, racing alongside Sophie Coldwell and Georgia Taylor-Brown.
Sian was able to record several top fifteen finishes in 2019 including a bronze medal at Kecskemét in the ETU Sprint Triathlon European Cup. She also featured in the British Mixed Relay team that finished sixth at the Weert ETU Triathlon European Championships in June.