Following the record-breaking results of new high-tech swimwear, FINA has amended its requirements for swimwear approval.

The new guidelines stipulate, swimsuits may not cover the neck or extend past the shoulders and ankles. They cannot be customized for individual athletes, maximum thickness is limited to 1mm (0.04 inch) and allowable buoyancy effect has been restricted. External aids such as pain reduction or electro-stimulation are also banned.

According to a press release, the new rules — drafted to regulate some of the advances, retain “the integrity of the sport” and keep the focus on the athletes’ “physical condition and preparation” — will be in place for the world championships starting July 17.

A list of approved suits is forthcoming from FINA, and starting next year the agency plans to limit the use of non-permeable materials.