Organisers have been forced to scrap the swimming leg of the Hamburg Ironman this Sunday due to high levels of algae in the city’s Alster river caused by the current heatwave.

The condition of the water has been deemed “potentially harmful to health”, so the swimming has been replaced by a six-kilometre (3.7mile) run.

“In order to protect all athletes, there will be a 6km run instead of the swimming,” organisers said in a statement.

After the hastily added short run comes the standard 180.2km bike race followed by a run over the marathon distance of 42.195km.

The excessive level of algae is due to the heatwave currently gripping northern Europe with temperatures set to again climb over 30 degrees Celsius on Sunday in Hamburg.

“We can’t risk the athletes’ health, so with a heavy heart, we decided to offer the duathlon variant on Sunday,” explained Bjorn Steinmetz, CEO of Ironman Germany. – Agence France-Presse

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