KINGSTON • Usain Bolt said advances in spike technology that could help wipe out his world records were laughable and that the new shoes would give their wearers an unfair advantage.
After athletes ripped through the record books in distance running with carbon-plated, thick-soled shoes, the technology has moved into sprint spikes, where although there is less time in a race for the advantage to make an impact, it is still enough to make a difference.
"When I was told about it, I couldn't believe that this is what we have come to, that we are adjusting the spikes to a level where it'll give athletes an advantage to run even faster," Bolt told Reuters in an interview from Kingston.
The 100m and 200m world record holder competed in Puma spikes throughout his career.
"It's weird and unfair for a lot of athletes because I know that in the past, they (shoe companies) actually tried and the governing body said, 'No, you can't change the spikes.' So to know that now they are actually doing it, it's laughable," added the former sprint king, who has won eight Olympic golds.
American Trayvon Bromell is favourite to take Bolt's 100m title in Tokyo. He is the fastest in the world over the distance this year with a time of 9.77 seconds.
But the 2015 world 100m bronze medallist is less convinced about the impact of the shoes.
"I don't think there's a lot of data to show that they're having such a big improvement," Bromell, who is sponsored by New Balance, told reporters last week.
While other companies now have similar shoe models, Nike looks set to dominate and is priding itself on being a leader in the technology.
"We're just smarter about how we engineer and assemble them," Nike said in an e-mail to Reuters.
Weighing in on developments in shoe technology, World Athletics said: "The current regulations (July 2020) were designed to give certainty to athletes preparing for the postponed Tokyo 2020 Olympic Games, to preserve the integrity of elite competition and to limit technological development to the current level until after the Olympic Games in Tokyo, across all events."
It said a working group on shoes aimed to set parameters to achieve a balance between innovation, competitive advantage and availability of the products.