By Lauren Ferri For Daily Mail Australia

Published: 08:05 EDT, 13 November 2020 | Updated: 08:05 EDT, 13 November 2020

Australian swimming legend Duncan Armstrong has been rushed to hospital after suffering a shock heart attack.

The 52-year-old suffered a cardiac arrest without warning on Tuesday and was rushed to a Brisbane hospital where he underwent emergency surgery.

Close friends and family were shocked when they were told about the surgery because Armstrong is known as an avid fitness freak, who keeps himself healthy.

Australian swimming legend Duncan Armstrong (pictured with news presenter Natarsha Belling in 2004) was rushed to hospital this week and had emergency surgery after suffering a shock heart attack

The 52-year-old suffered a cardiac arrest without warning on Tuesday and was rushed to a Brisbane hospital where he underwent surgery immediately

The swimming legend is still in intensive care but doctors say he is expected to make a full recovery, the Daily Telegraph reports. 

Family have been told he is 'doing fine' but he is currently not allowed any visitors until doctors take him out of the intensive care unit.

Armstrong is best known for his stunning victory in the 200m freestyle in the 1988 Seoul Olympics. 

He also claimed silver in the 400m freestyle the same year. 

He was ranked 46th in the world going into the Olympics but quickly produced one of the biggest underdog wins in history.

The performance in the 200m freestyle 32 years ago was groundbreaking for Australian swimmers.  

Armstrong, aged just 20 at the time, broke the world record and beat American legend Matt Biondi and Germany's Michael Gross.

Close friends and family were shocked when they were told about the surgery because Armstrong (left) is known as an avid fitness freak, who keeps himself healthy

Armstrong is best known for his stunning victory in the 200 metre freestyle in the 1988 Seoul Olympics

In the lead up to the race Armstrong swam 20km per day and was told by legendary swimming coach Laurie Lawrence to swim as close to Biondi all race.

The 52-year-old retired from Olympic swimming after the 1992 Barcelona Games after the Australian team was disqualified from the 4x200m event final.

He has since become a swimming commentator on Channel Nine and Fox Sports

In 1989 Armstrong received an Order of Australia Medal and was inducted into the Sport Australia Hall of Fame in 1993, the International Swimming Hall of Fame in 1996 and the Queensland Sport Hall of Fame in 2009.  

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