Running a Marathon in August in Tokyo: Hot Town! Summer in the City! Back of My Neck Getting Dirty and Gritty!

testing-new-road-material
Testing the new high-tech road surface August, 2016

The average temperature in Tokyo in July and August is around 30 degrees Celsius or 86 degrees Fahrenheit. But on the roads of Tokyo, after absorbing day after day of heat, can get as hot as 50 degrees Celsius, or over 120 degrees Fahrenheit.

That’s hot!

And that’s not counting the dreadful humidity that time of year in Tokyo. I hated summers in New York City, but they’re worse in Tokyo.

Now, imagine running 42 kilometers on those roads, in that heat and humidity, because the marathons for women and men are scheduled respectively on August 2 and 9 in 2020. Researchers say that on average optimal times to run a marathon are temperatures of around 6 degrees Celsius or 43 degrees Fahrenheit. Average body temperature is around 37 degrees Celsius and research also shows that running performance drops significantly if body temperature rises above 38.8 degrees celsius, according to this article.

At 38.8 C, the body can no longer effectively cool itself and it begins to divert blood to the skin to help keep it cool. This decreases the amount of blood available to carry oxygen to working muscles, which affects performance.

In intense hot weather athletic events, as the body becomes severely dehydrated, the result can be heat exhaustion, heat cramps, heat stroke, heat-induced coma and then even death.

road-surfaces-for-marathon
The examples of the high-tech road surfaces: the one on the left is the water-retaining material and the one on the right is the ceramic-based sprayed material

Clearly, organizers of the Tokyo Olympics want to avoid both cramps and death. What are they going to do? They’re going to turn the roads white. On August 31, 2016, a special event was held on a 250-meter stretch of road in the middle of Tokyo that incorporated two pieces of heat-reducing technology:

  • a ceramic-based spray coating with insulating properties which resulted in a whitish-colored road that reflects the sun’s infra-red rays, as well as
  • another road material that has water-retaining properties, by which water is retained and slowly evaporated, thus cooling the roads.

These two technologies will be combined to build out a road of some 21 kilometers, according to a television broadcast I recently saw, and allows the entire 42-kilometer race to be run, presumably, on a road much cooler than what they would experience today.

Olympic marathon runner Toshihiko Seko and Paralympic wheelchair marathon runner Nobukazu Hanaoka, were on hand on August 31 to test them out the new road. Their reaction?

  • “The heat-insulating paving was clearly cooler,” said Seko after a test run on the road.
  • Hanaoka said: “The wheels did not slip when I applied the brake, even when the surface was wet.”

Other ideas being explored to keep the road and the runners cooler are:

  • More shade along the course
  • An earlier start in the day
  • Routing the course through more open areas with greater wind movement
  • Routing the course near water and presumably lower temperatures
  • Placement of cool mist stations along the course