New calendar likely because of climate change - Coe

The global calendar of Olympic sports may need to be "re-engineered" amid the challenges posed by climate change after athletics' biggest stars had to contend with searing temperatures in Tokyo, World Athletics president Sebastian Coe says.

The World Athletics Championships concluded on Sunday night, following nine days of competition during which the sport's household names lit up Japan's National stadium, which four years ago hosted the Olympics behind closed doors because of the coronavirus pandemic.

The opening days of the championships were dominated by discussion around the conditions the athletes had to contend with - particularly in the endurance events - as temperatures exceeding 30C were accompanied by stifling humidity above 90%.

In addition to the quadrennial Olympic Games and biennial World Championships, World Athletics will next year stage its inaugural Ultimate Championships in Budapest to bridge the gap between its major events and provide a definitive conclusion to the 2026 season.

But Lord Coe said events such as the marathon may need to be held separately, at a different time of the year, at such competitions to protect athletes from unsafe conditions in future.

"Yes, I do see that," Coe told BBC Sport. "That's not easy because you're going even into the autumn, early winter months to cities that are still very hot.

"But I do think this is probably going to have to happen at some stage, and sooner rather than later."

According to Coe, World Athletics research has found that 70% of athletes report that climate change and the heat is impacting their training and competition programmes.

The 68-year-old said "governments haven't really stepped up to the plate" on the issue and added: "I can't see beyond the inevitability of having to collectively, as Olympic sports and probably the Olympic movement, really re-engineering what the international calendar looks like.

"From World Athletics' point of view, there will be some branding issues but I'm not sure that we can go on asking some of our endurance-based athletes to be competing at times of the year which are really are going to hit their performances and are probably putting them at risk as well.

"This has to be addressed."

Coe also confirmed that all athletes who competed in the female category at the World Championships had undergone gene testing - and that the test is here to stay.

However, he reiterated that details of any athletes who may have been prevented from competing as a result of the test, carried out via cheek swab, will remain confidential.

Its introduction comes amid reports, external that between 50 and 60 athletes who went through male puberty have been finalists in the female category at global and continental track and field championships since 2000.

Pole vault superstar Armand Duplantis, Americans Sydney McLaughlin-Levrone and Noah Lyles, and Kenya's Faith Kipyegon were among the sport's big names who captivated often sell-out 60,000 crowds at Japan's National Stadium.

Swedish 25-year-old Duplantis produced arguably the standout moment when he soared to his 14th world record with his final attempt after winning a third consecutive world title.

McLaughlin-Levrone went close to the controversial 40-year women's 400m world record, while compatriot Lyles emulated Jamaican great Usain Bolt with a fourth consecutive world 200m title and Kipyegon won a historic fourth world 1500m title.

Speaking at a closing news conference on Sunday, Coe said: "I think our sport is in really good shape. We have broader appeal and a greater level of following than we have had for a long, long time.

"We have athletes that are performing as well as any generation I have witnessed."

Next year, they will compete in Budapest as World Athletics hosts its three-day Ultimate Championships featuring world champions, Diamond League winners and the top performers of 2026 - and which offers a $10m (£7.5m) prize pot.

Earlier this year, the inaugural season of Michael Johnson's Grand Slam Track - which excluded field events - ended with the final leg being cancelled because of financial concerns and its future appears in doubt with some athletes still yet to receive money.

Coe said World Athletics intend to use the Ultimate Championship to test ideas which could later become part of the sport's established major stages.

"We've got a four-year cycle and one of those years we don't get the billion eyeballs on our sport. As a global sport we can't afford that," said Coe.

"We thought about what we can do that is different and can be an incubator for change, where we can introduce and test things and maybe they turn up here in a World Championship.

"I think it will be it'll be a great addition but there is a lot more work to do."

Sporting icon Bolt, winner of eight Olympic gold medals, told BBC Sport he believes the Ultimate Championships is a "good start" as the sport seeks to grow.

"The sport needs to evolve and I feel like track and field is moving in the right direction," Bolt said.

"Track and field is probably one of the poorest sports and it's one of the biggest sports, so the incentive is very big and I'm happy for the athletes because they deserve it."

Regarding the high level of performances witnessed in Tokyo, and increasing standards overall, Coe pinpointed technological advances in the synthetic track surface, the shoes worn by the athletes, and improving coaching skills and methods.

Coe said: "Some of the performances we've seen here are simply jaw-dropping.

"The lovely thing about it is that the sport is moving ahead both as track and field in pretty much the same progress."

He added: "There's never enough prize money for the athletes, we always want more. Where possible, we want the athletes to benefit from the proceeds of growth."