With science and technology advancing athletic performance across all sports, swimming's Fédération Internationale de Natation (FINA) governing body has decided to limit the amount and type of materials that can be used to make the fancy swimsuits worn by elite swimmers such as Michael Phelps.

The new rules won't affect the FINA World Championships taking place this week at the Foro Italico in Rome, where six new world records have already been set by swimmers in suits made from materials such as polyurethane, and Phelps has already won a gold metal. (Phelps won eight gold medals at the Summer Olympics in Beijing last year.)

Such attire—more like a wetsuit than a swimsuit—is believed to have contributed to the 108 world records set last year and nearly 30 so far this year, the Associated Press reports.

FINA has for several months been reviewing procedures for swimwear approval, namely in the areas of the swimsuits' material, thickness, use, shape and availability. The organization voted overwhelmingly last week to limit swimsuit coverage to between the waist and knees for men, and not beyond the shoulders or below the knees for women, according to the AP. The new rule also says suits must be made from textiles (as opposed to titanium alloys and other composites) although FINA has yet to provide a more complete definition of this.

Speedo, one of the most prominent swimsuit companies, makes body-hugging apparel that mimics shark skin, alternating between something like the rough dermal denticles found around the fish's nose and smoother derma located farther back on its body, according to a 2004 Scientific American article examining the technology behind these swimsuits. Some Speedo suits also feature titanium-silicon scales on the inner forearm that grip the water better on down strokes, as well as rubber bumps across the chest to help reduce resistance. TYR Sport, Inc. and Nike are two other companies that make high-tech swimwear.

Image of Phelps © moose manda via Flickr.com