Heat fears mean Tokyo Olympic marathons might move to 'significantly' cooler Sapporo
IOC panel currently consulting with sports governing bodies
The International Olympic Committee wants to move the Tokyo Games marathons 800 kilometres (500 miles) north to avoid the searing heat in the city.
The IOC detailed a new plan Wednesday to stage the marathons and race walking events in Sapporo, the host city of the 1972 Winter Olympics, which "will mean significantly lower temperatures for the athletes."
Forecast temperatures in Sapporo are "five to six degrees centigrade cooler during the day than in Tokyo," the Olympic body said.
"The Olympic Games are the platform where athletes can give 'once-in-a-lifetime' performances, and these measures ensure they have the conditions to give their best," IOC president Thomas Bach said in a statement.
An Olympic panel has been assessing heat and weather issues for the July 24-Aug. 9 Summer Games and is consulting with sports governing bodies.
The marathons were already due to start at 6 a.m. in Tokyo to ease the heat effect on runners. The men's 50-kilometre race walk final was slated for a 5:30 a.m. start.
Olympic panel to discuss heat measures later this month
Marathons were run after midnight in 38C this month at the track and field world championships in Doha, Qatar.
The IOC said it informed the track body and said it will consult with Olympic teams and broadcasters.
An Olympic panel overseeing games preparation will discuss heat measures at its Oct. 30-Nov. 1 meeting in Tokyo.
"These include better shade, water sprays, better access to water supplies and an initiative to help the athletes in their preparations," the IOC said.
The plan driven by increasing summer heat cuts into a key promise of Tokyo's bidding, first for the 2016 Olympics won by Rio de Janeiro and then its successful 2020 campaign, to deliver a "compact games" with 85 per cent of venues in an 8km city centre cluster.