World Athletics set new rules on running shoes

World Athletics have cleared distance athletes to keep wearing the controversial shoes that Eluid Kipchoge wore when he became the first human to break the two hour barrier for the marathon.

The governing body of track and field acknowledged that although shoe technology poses a risk to the sport it still cleared distance runners to keep wearing the Nike designed Vaporfly shoes as worn by Kipchoge in Vienna.

However, World Athletics have set guidelines that dictate that a shoe must have been available to buy for at least four months before it can become eligible for competition. New shoes must also have soles no thicker than 40mm and can not contain more than one rigid, embedded plate.

If a shoe is not openly available to all then it will be deemed a prototype and use of it in competition will not be permitted, the statement said.

The new ruling will come into effect on April 30, four days after Kipchoge defends his London Marathon title.

Independent research showed sufficient evidence to raise concerns that the integrity of the sport might be threatened by the recent developments in shoe technology, the Monaco-based governing body said.

An expert working group will be created to assess new shoes entering the market.

Still, the more established Nike style called Vaporfly, increasingly favoured by top marathon runners, can be worn.

"As we enter the Olympic year, we don't believe we can rule out shoes that have been generally available for a considerable period of time," World Athletics president Lord Sebastian Coe said.

"But we can draw a line by prohibiting the use of shoes that go further than what is currently on the market while we investigate further.

"I believe these new rules strike the right balance by offering certainty to athletes and manufacturers as they prepare for the Tokyo 2020 Olympic Games".

The Tokyo Olympics open in just under six months.