World Athletics ruled Friday that a shoe recently developed by sports equipment manufacturer Nike Inc., can be used in competition at this summer's Tokyo Olympics.

The shoe, marketed by Nike as the Vaporfly, incorporates a carbon fiber plate fused with a foam layer that acts like a spring, ostensibly propelling runners forward with each stride.

World Athletics' new rules prohibit shoes with soles thicker than 4 cm and with more than one plate — unless the second plate's only function is to attach spikes to the shoe.

The body also said that from April 30, only shoes that have been available for purchase on the open market for at least four months can be used in competition, enabling the Nikes to qualify for Tokyo 2020.

"It is not our job to regulate the entire sports shoe market but it is our duty to preserve the integrity of elite competition by ensuring that the shoes worn by elite athletes in competition do not offer any unfair assistance or advantage," World Athletics President Sebastian Coe said.

"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, 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."

World Athletics said there is evidence that the new shoes provide a performance advantage, and that further study will be done.