The next question in our ‘Ask a Sports Engineer’ series tackles some of the cutting edge equipment that is used across a wide range of sports: the skin suit.
When talking about skin suits we are referring to the tight, all-in-one outfits worn by Swimmers, Cyclists, Speed Skaters, Skeleton sliders and Athletes alike. This technology can provide great performance gains to athletes and as a result can also be the source of great controversy as people try to understand the technology. There are two main areas of benefit to athletes when using skin suits: compression and drag reduction.
Wearing carefully designed garments which apply compression to specific areas of muscle is thought to improve blood flow and to help the body to oxygenate muscles quickly and, more importantly, to get rid of waste products such as lactate. In terms of evidence that compression clothing does improve performance during competition, it is hard to be conclusive as there is a reasonable amount of argument on both sides within the literature.
Compression clothing has also been developed by Adidas who have produced garments that store energy and give you a reported 5% more power when contracting your muscles, as explained in the video below. This technology is used in Athletics, Football and many other sports where a 5% improvement can make huge differences in the outcome, so if it performs as claimed, is it fair?
Arguably the main advantage of skin suits is the drag reduction which they can provide. Drag force is the force that acts in the opposite direction to the way you are moving and is produced by fluid as it pushes you back and flows around you. Any reduction in drag means you have to exert less force to move, which is obviously a big help, especially in elite sport.
As with many innovations in the engineering world, the inspiration comes from nature. Sharks have been keenly researched in recent years to find out what makes them such fast, smooth swimmers and to learn how we may mimic them. Research has found that they have quite an unusual physiology, in that their muscles attach directly to their skin, which makes it a very solid but controllable surface. They also have special v-shaped grooves called ‘riblets’ which run between small tooth shaped scales. This surface helps to maintain a turbulent (messy) flow in the layer of water close to the skin, which reduces the amount of friction in the flow and reduces drag by as much as 10% compared to a smooth surface.
Magnified shark skin, showing the riblet pattern (Courtesy of Carolina Biological Supply Company)
The knowledge gained in the research of shark performance has led to a series of inspired designs over the last 15 years, Speedo’s original ‘fastsuit’ directly mimicked the riblet texture of a sharks’ skin and featured prominently in the Sydney Olympics in 2000.
The design saw a two more iterations, culminating in the Speedo swimsuits which won so many medals at the Beijing Olympics (below).
Swimmers pose in the Speedo LZR skinsuit
The same principles of subtle design changes inspired by nature are applied to the clothing used in sports other than swimming too. The drag reduction principles will still hold true out of the water, but the differences when performing in air may be less noticeable due to the fact that water is over 800 times denser than air and provides more resistance.
Nike’s Swift Skin suit was developed for speed skaters (in collaboration with 3M) at the Winter Olympics and was composed of 6 sections, each with different properties. The sections were all specifically designed for the part of the body it was surrounding and had been designed based on wind tunnel tests with skaters that identified areas of high drag. In advance of the Olympics this year, Nike has release a ‘turbosuit’ with a dimpled texture and claims of performance improvement.
The un-level playing field
At the top end of elite sport there are usually very small margins between the best competitors, all the athletes are technically very capable, so any small improvements that can be achieved through training or apparel will be noticed. It’s likely that you will see many medals won and world records broken by athletes wearing skin suits this summer at the London Olympics and also at the Winter Olympics in Sochi in 2014. This will be great for spectators and for sporting progression, as it continues to push the boundaries of achievement and inspire new people.
Is it a genuine achievement if you beat someone due to the clothes you are wearing? Should everyone compete in the same kit to meet the Olympic value of fair play? Let us know your thoughts.