Paris (AFP)

Shaken by the appearance of Nike's "magic" shoes which made it possible to achieve extraordinary performances on the road, the International Athletics Federation tried Friday to put some order in the house by prohibiting the use of prototypes in competition and regulating the characteristics of sneakers.

"From April 30, 2020, any shoe must be available for purchase by any athlete on the market (online or in store) for a period of four months, before it can be used in competition," said World Athletics. in a press release after approving the recommendations of a panel of officials, athletes, doctors, scientists and lawyers.

The world body has also clarified its regulations on the technical characteristics of shoes (size of the sole, number of plates added to the sole) and announced that a group of experts will now examine any new technology before validating it in competition.

This clarification comes at a time when the debate on new shoes has been raging since the meteoric success met both by professionals and amateurs by the Nike Vaporfly, with a carbon blade in the sole. According to a statistical analysis from the New York Times, runners wearing Vaporfly run between 4 and 5% faster than others on the marathon.

For the International Federation, it was urgent to act when other brands are already working on shoes using similar technology.

- "Draw a yellow line" -

Faced with the same phenomenon as the International Swimming Federation, which was forced to ban polyurethane coveralls in 2010 after an avalanche of records, World Athletics therefore decided to cut the pear in half.

Concretely, the Vaporfly Next% shoe, marketed since 2017 and with which the Kenyan Brigid Kosgei was equipped when breaking the world record for the Paula Radcliffe marathon (2 h 14 min 04) on October 13, 2019, is not prohibited and could be worn at the Tokyo Olympics in August. Consequently, all the times established by the Vaporfly available commercially remain valid.

However, the Vaporfly prototype called Alphafly, used by his compatriot Eliud Kipchoge on October 12 to break the symbolic barrier of 2 hours on a marathon (1 h 59 min 40 sec during an unofficial race), will not be authorized because it uses three carbon blades in its sole.

The thickness of the sole of a road running shoe cannot now exceed 40 mm (the sole of Vaporfly Next% is approximately 31 mm) and it is prohibited to insert more than one plate of another material (carbon blade, plastic ...). For the "points" (track shoes), a second plate is authorized but must only be used to attach the "nails" to the sole, the maximum thickness of which is 30 mm.

"Our job is not to regulate the entire sports shoe market, but our duty is to protect the integrity of elite competitions by ensuring that the shoes worn during these races do not offer an advantage or assistance unfair, World Athletics President Sebastian Coe said in a statement. In the Olympic year, we do not want to ban shoes that have been available for a relatively long time, but we can draw a yellow line to keep it from going further than what is available on the market while we continue our studies. "

© 2020 AFP