Photo/IllutrationIn the early morning on Aug. 8, a runner wipes off sweat in the sweltering heat as he passes by the Imperial Palace, near the 33-kilometer mark of the marathon course for the 2020 Tokyo Olympics. (Asahi Shimbun file photo)

The sweltering heat that Tokyo experiences in August has led the 2020 Games organizers to move the starting time of marathon events up a second time, to 6 a.m.

The Tokyo Organizing Committee of the Olympic and Paralympic Games plans the 6 a.m. start, an hour earlier than previously scheduled, to reduce the health risks among athletes, spectators and participants in the events.

The women's marathon is scheduled for Aug. 2 and the men’s competition for Aug. 9.

The committee will discuss the new plan with members of the Coordination Commission of the International Olympic Committee, who are currently visiting Japan. New schedules are expected to be announced on Dec. 5.

When Tokyo bid for the 2020 Summer Olympics, it proposed starting the marathon competitions at 7:30 a.m. In July, however, the Tokyo Games organizers decided to move the time up to 7 a.m. in light of concerns over the high temperatures and humidity common in the capital in August.

The change was approved by the IOC. But two groups of doctors--the Japan Medical Association and the Tokyo Medical Association--called on the committee to move the start to 5:30 a.m. The committee has been re-examining the possibility.