How Do Swim Suits Help Improve a Swimmer's Performance?

Swimming is a wonderful way to keep fit but the equipment you use can make you faster.
Christopher McFadden

Swimming is one of the best ways to get, and stay, in shape. But why do professional swimmers wear such tight-fitting suits?

Here we explore the science behind them and reveal how much of an impact high-tech suits can make to a swimmer's performance. 


Why do swimmers wear tight suits?

Swimming suits are primarily designed to not only preserve your dignity but also help you swim more efficiently. The main problem to overcome when moving through the water is something called drag. 

You experience drag all the time, but in the air, it is easily overcome when walking or running. If you want to feel how strong drag can be in the air, hold your hand (obviously be careful) out of the window in a moving car.

That backward force imparted on your hand is drag in action. And it can be surprisingly strong. 

This is a basic component of fluid dynamics and engineers work tirelessly to make vehicle, ship and aircraft designs in such a fashion as to reduce its impact. 

When the medium is denser, like water, drag becomes more of a problem when trying to move through it. Water is pretty sticky and at higher speeds can be a serious problem for any sea vessel.

For swimmers, water effectively pushes back on them as they attempt to push through it. Not only that, but a small wave (bow wave) is produced in front of the swimmer adding to the impact of drag.

For swimmers, even a small improvement in drag resistance can be a game-changer in competitions. So much so, in fact, that after the 2009 World Swimming Championship, Speedo's LZR suits were effectively banned by FINA in 2010

how swimsuits work dive
Source: Irven Simmons/Flickr

Apart from the very high tech solutions devised by companies like Speedo, even regular swimsuits can help improve swimmer performance in the water. 

One of the reasons that swimsuits are tight to the body is to help control the shape of the wearer's body. It effectively helps to make them more hydrodynamic. 

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Higher quality suits are also made of special materials that repel water multiplying the suit's ability to reduce drag. What is interesting is that you don't even need to be an Olympian to notice the difference. 

If you wore one it is highly likely you'd make a better time per lap than just wearing trunks or swim shorts (as a man). 

How do swimsuits make you swim faster?

We've already touched on one quality of swimsuits that help you swim faster - they are tight to the body. This helps them make you more streamlined in the water. 

Many professional swimmers will also shave most of the hair on their body to further reduce drag in the water. Caps are usually also worn to cover their heads and keep their ears tucked in. 

But the tightness of swimsuits can also help reduce the build-up of lactic acid in your muscles. Lactic acid is the main culprit for your muscles feeling tired, or getting a stitch when you perform an aerobic exercise like swimming. 

But swimsuits can do a lot more than that. 

High-quality ones tend to be made from specially designed materials that provide small, but significant, advantages over less expensive alternatives. 

Most swimsuits today tend to be made from nylon or spandex. Both of these synthetic fibers not only help make the suit tight but are also hydrophobic in nature. This property enables them to be water-resistant which can reduce the effects of drag by as much as 8%

They, in effect, repel water away from them helping the swimmer better "cut" through a body of water. 

how swim suits work race
Source: Tony Baldasaro/Flickr

Their seams are also specially designed to help improve swimming efficiency. The way that the materials are held together in the final suit can also play a vital role. 

Bonded, rather than sewn seams can help reduce drag by as much as 6%. Pretty impressive. 

Some of the most advanced suits even attempt to mimic the dermal denticles of sharks. This further enhances their ability to reduce drag and increase speed

What should I bring to swim practice?

The exact kit you might want to bring to swimming lessons will depend on your ambitions. If its purely recreational then the quality of the equipment you use is less important.

That being said, as a minimum you should consider bringing the following: -

  • Swimming shorts or swimsuit depending on your sex.
  • Goggles.
  • A swimming cap (this is sometimes mandatory at certain pools for hygiene purposes).
  • Towels if none are supplied by the pool.
  • Swim bag to carry everything in.
  • If you have any skin infections like verrucas or athletes foot, for example, you should also wear footwear in communal rooms and swimming shoes when in the water to prevent spreading them to other swimmers. That being said, there are some other skin complaints that you should avoid swimming until the disease has been treated

If you are more of a competitive swimmer, you might want to consider some more high tech options: -

  • High tech swimsuit - You might want to fork out for Speedo's LZR or another alternative. 
  • Streamlined, high drag reduction goggles - These should be tight but comfortable, have a low profile with a hydrodynamic shape.
  • Drag resistant swim caps - These should be durable, tight and wrinkle-free. Some of the high-end caps can reduce drag by between 3 and 6 %. 

What suits do Olympic swimmers wear?

When it comes to competitive swimming events like the  Olympics, even shaving off a fraction of a second can make all the difference between a gold and silver medal. While the swimmer's level of fitness and technique are of primary importance, the equipment they use can also provide a significant advantage. 

After the momentous events of the 2008 Beijing Olympics when high-tech swimsuits literally made waves in the competition, FINA (the International Federation of Swimming) effectively banned their use in high-level competition swimming. 

The official FINA rules are pretty prescriptive when it comes to what can, and cannot be worn during competition. 

For men, torsos and lower legs must be bare, and swimsuits must be made from woven textiles. Nowadays, most male swimmers will wear tight-fitting swim shorts called jammers

These swim garments cover the swimmer's lower body from waist to just above the knee. FINA lists the approved suits by manufacturer and style on their website. Swimmers can wear full-body suits only for open-water events.

For women's suits, they are not allowed to cover the neck or extend past the shoulders or below the knee. In both cases they must not "offend morality and good taste (in particular, but not exclusively, because of the cut of the suit)." - FINA