Triathlon and gold medal prospect Hayden Wilde says water currents are as much an issue as quality of the Seine ahead of the men's triathlon.
Water quality in the river Seine is again under the spotlight with rain in Paris threatening to turn reduce the Olympic men's triathlon to a duathlon.
Readings have reportedly shown the water quality was below the standard deemed safe to swim just days before the event.
Organisers remain confident the race will still comprise the traditional triathlon.
Hayden Wilde told First Up on Monday that the water currents were as big an issue as the quality.
Currents nearly three times as strong as normal have been detected making the swim leg a tougher prospect.
Wilde said he had been putting in real effort to improve his swimming, recently taking around five seconds off his 100m segments.
"There's been a lot of blood sweat and tears. There were moments where I was swimming terribly and then moments where I had got to the other side and was swimming well.
"We have done a lot of biomechanical work to improve my technique."
To combat the expected 30C heat, athletes would begin to hydrate now to have enough water on board.
And Wilde said the highest temperatures weren't expected until the end of the race, making conditions a bit easier for the event.