Organizers of the 2020 Olympic Games in Tokyo said Wednesday they intend to change the start times of some athletics, cycling and rugby events in an effort to reduce the risk posed by extreme heat.

Speaking at the conclusion of the latest meeting of International Olympic Committee's coordination commission, which monitors games preparations, Tokyo 2020 President Yoshiro Mori also revealed that the organizing committee will continue to plan for a boxing tournament, despite the threat of the sport's exclusion from the games.

The risk posed to athletes, spectators and workers by extreme heat has become a major issue after a July heatwave saw a record high temperature of 41.1 C near Tokyo and caused 96 deaths in the capital alone.

The Japan Medical Association and the Tokyo Medical Association called for schedule changes, warning organizers of possible heat-related deaths.

Mori said the start times of the marathon and 20-kilometer race walk events will be moved forward by one hour to 6 a.m., subject to the expected approval of the International Association of Athletics Federations.

All of the morning sessions in the rugby sevens tournament will now start at 9 a.m., one and a half or two hours earlier than previously planned, while the mountain bike events will be pushed back from a 2 p.m. start to 3 p.m.

The IOC's John Coates, chairman of the coordination commission, said its expert working group had recommended the marathon and race walk events start at 5:30 a.m. or 6 a.m.

"The organizing committee regards this (the heat) as one of the most important issues it faces, and concerns have been raised from the stakeholders, including (IOC) President (Thomas) Bach," Mori said.

Coates said this year's heatwave was "abnormal" but that the heat risk "will continue to be front of mind for us".

Asked about the possible negative impact on Japanese television broadcasters of the earlier start times in athletics, Tokyo 2020 CEO Toshiro Muto acknowledged there could be "several problems" but said mitigating the effect of the heat on athletes and spectators was the priority.

Tokyo has been under pressure to reduce costs by the IOC, which is desperate to drive down games' budgets after a succession of potential host cities pulled out of hosting races due to fears of spiraling costs.

There have been concerns the extra anti-heat measures -- such as more medical resources, non-heat-reflecting paving, water sprayers and more shaded areas for spectators -- would drive costs up.

However, Coates said he was confident that version 3 of the games operating budget, due on Dec. 21, would be balanced.

"I am very confident it will be a balanced budget, which means operating costs will not cost the taxpayer anything," Coates said of the organizing committee budget, while acknowledging that government money is being spent on "legacy" aspects such as venues.

Boxing's place at the games was thrown into doubt last week when the IOC's executive board announced an inquiry into the finances, governance and ethical standards of the International Boxing Federation, with a decision on the sport's inclusion to come next June at the latest.

The IOC put a freeze on the governing body's planning for the Tokyo Games and prohibited contact between it and the organizing committee.

But Mori said planning for the boxing tournament was discussed during the coordination commission meetings, which ran from Monday to Wednesday, and it was agreed that issues which normally required governing body approval would be decided upon by the IOC until the issues are resolved.