New Zealand triathlete Ryan Sissons admits the Tokyo Olympic race next year may not be much fun because of the heat.
Concerns were raised earlier this month about athlete safety after a heat wave in Japan killed 57 people.
Ainsley Thorpe, Nicole van der Kaay, Sophie Corbidge, Hayden Wilde, Sam Ward, Tayler Reid and Ryan Sissons are in Tokyo for this week's Triathlon Olympic Test Event.
The New Zealand athletes spent a week training and acclimatising to the heat in Sakata before travelling to Tokyo.
Sissons, who is attempting to qualify for his third Olympics, says the conditions are testing.
"The heat training has been really important, and we've done a lot of that. It's a two-hour race finishing around 9.30am with a predicted 'feels like' temperature of around 40-degrees, so that's challenging.
"Keeping the body cool and the heart rate in check in the heat is something I've been looking at in training, trying to figure out how to keep my body as cool as possible while still going really hard," Sissons said.
The Olympic Test Events are held on the course for next year's Olympic Games and are a key part of New Zealand Team athlete preparation for Tokyo 2020.
"This is one of qualification races for Tokyo, for us it's great to be able to race on the Olympic course in the conditions the Olympic Games will be in. Athletes go differently in different conditions so to go well here would be a good sign.
"This is one of the races I've been targeting all season, I started off slowly but am working into the season well and am excited for the race," Sissons said.
As well as the individual races the new Olympic discipline of 'mixed team relay' will also be contested, where two male and two female athletes race a sprint triathlon distance.
The women's race will be contested on Thursday, with the men's to follow on Friday and the mixed team relay will be contested on Sunday 18 August.