But the federation’s rules have become more ambiguous since Pistorius prevailed in the Court of Arbitration for Sport.
The I.A.A.F.’s Rule 143 now says that shoes “must not be constructed so as to give an athlete any unfair additional assistance, including by the incorporation of any technology which will give the wearer any unfair advantage.”
What constitutes an unfair advantage? It is not explained.
The rule does say that “all types of competition shoes must be approved by the I.A.A.F.” But Nike said that it was unaware of any formal approval process and that shoe companies do not routinely submit their shoes for inspection.
Nike officials said they were working closely with the I.A.A.F. on course design and drug testing for the Breaking2 project and would be “sharing” the shoes with the governing body. They also noted that carbon-fiber soles have been used before in the running shoe industry.
“We’re giving our athletes a benefit within the rules as they’re written,” said Schoolmeester, the Nike executive, adding, “We’re not using any sort of illegal springs or anything like that.”