Runners are apparently getting an unfair advantage by wearing Nike Vaporfly trainers, according to a new report.
The range of shoes has been criticised by some amateur athletes who think they create an uneven playing field, the Times reports.
The newspaper claims laboratory tests suggest runners could slash their times by at least 4%.
It added the shoes could give runners a slightly longer stride it attributes to a carbon-fibre plate in the sole and a spongy heel, which combine to create “more propulsion”.
Kent Athletics Club member Owen Hind said most of the people he ran with now wore the £250 trainers.
He said: “The carbon plate-foam combination is unlike anything else that has ever been on the market.
“The plate clearly has a spring effect, adding distance to each stride and requiring less force in leg strike for same speed.”
He added he was concerned professional runners getting sponsored by Nike could have an unfair advantage on other competitors.
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A technical committee is currently reviewing the Nike Vaporfly shoes and will report back to World Athletics with its recommendations by the end of the month.
It could suggest sole thickness and carbon plates are limited in the production of running trainers, the Times added.
Currently, UK Athletics only limits sole thickness and materials in the long and high jump events.
Yahoo UK has approached Nike, World Athletics and UK Athletics for a comment.