Competitive swimwear

A mixed-sex pair in their swimsuits, participating in FINA World Championships of synchronised swimming.

A woman wearing a racing competitive racerback bikini

Competitive swimwear refers to the swimsuit, clothing, equipment, and accessories used in the aquatic sports of swimming, diving, artistic swimming, triathlon, and water polo.

Some swimsuits are designed specifically for swimming competitions where they may be constructed of a special low resistance fabric that reduces skin drag. Most competitive swimmers wear special swimsuits including partial bodysuits, racerback styles, jammers and racing briefs to assist their glide through the water thus gaining a speed advantage.

For diving in water temperatures above 25 °C (77 °F), special bodysuits called "dive skins" are worn. These suits are made from spandex and provide little thermal protection, but they protect the skin from jellyfish stings, sunburn, and abrasion. This kind of suit is also known as a 'Stinger Suit'. Some divers wear a dive skin under a wetsuit, which allows easier donning and (for those who experience skin problems from neoprene) provides additional comfort.

Unlike regular swimsuits, which are designed mainly for aesthetic appearances, swimsuits intended to be worn during competitions are manufactured to assist the athlete in swimming competitions. They reduce friction and drag in the water, increasing the swimmer's forward motion efficiency. The tight fits allow for easy movement and are said to reduce muscle vibration,^[1] thus reducing drag. This also reduces the possibility that a high-forward dive will remove a diver's swimwear. Starting around 2000, to improve the effectiveness of the swimsuits, engineers have taken to designing them to replicate the skin of sea-based animals, sharks in particular.

In July 2009, FINA voted to ban non-textile (non-woven) swimsuits in competitive events from 2010. The new policy was implemented to combat the issues associated with performance-enhancing swimsuits, hindering the ability to accurately measure the performance of swimmers.^[2] Subsequently, the new ruling states that men's swimsuits may maximally cover the area from the navel to the knee, and women's counterparts from the shoulder to the knee.^[3][4]

Some swimmers use a specialized training suit called drag suits to artificially increase drag during practice. Drag suits are swimwear with an outer layer of looser fabric – often mesh or nylon – to increase resistance against the water and build up the swimmer's endurance. They come in a variety of styles, but most resemble a looser fitting square-cut or swim brief.