Engineering a Faster Olympic Swimmer

The Olympics are often thought of as competitions of human strength and skill. However, the world of swimming has changed drastically in the last decade thanks to engineers and researchers working on something often overlooked in swimming competitions: the swimsuit. Swimsuits of today do more than protect the modesty of the swimmer. The materials used are designed to reduce drag and increase buoyancy while also improving the muscle power of the athletes. Pretty soon, using these swimsuits, athletes began smashing previous world records.


Four swimming events. (A) Men 200 m Breast. (B) Men 50 m Freestyle (C) Women 100 m Back (D) Women 1500 m Freestyle. Red lines mark the introduction of full-body polyurethane suits. Adapted from Berthalot et al. Materials Today 2010

To better understand how these swimsuits could lead to a sudden burst in performance, we’ll look at the physics of swimming. As you swim there are four forces acting on your body. First is gravity. Like always gravity is trying to bring you down. Second is the buoyant force. Being in the water displaces some amount of water molecules. If the swimmer weighs more than the water the swimmer displaces, they sink. This is why dense objects sink and light objects float. Third is thrust, the force from the swimmer pushing against the water with their hands, arms and feet. The last force is drag. This is the force of the water resisting your motion.


Free body diagram showing swimmer in one-piece swimsuit (gray) and the four forces acting on them. Arrows are drawn to show how much they affect the swimmer

The type of swimsuit can change how much of a role the different forces play. A full-body polyurethane suit like the ones worn in 2008 allowed water to slide off the suit instead of allowing it to pass through. This reduced the drag the swimmer experienced allowing them to swim faster. Adding to that, air pockets in the suit increase the buoyant force keeping the swimmer closer to the surface. Being on top of the water instead of farther down further reduces the drag on the swimmer.


Free body diagrams showing how the swimsuit worn (gray) changes how the swimmer (blue) experiences the same four forces. Reduced drag and increased buoyancy allowed swimmers to swim faster than ever.

Swimming with less drag has allowed the swimmers to swim faster and smash previous world records. The technology in the suits led the International Swimming Federation (FINA) to ban suits made out of rubber-like materials such as neoprene and polyurethane. Current restrictions on suit design include limits on how much of the body the suit can cover, what material it can be made of, how thick the suit is, and prohibits “outstanding shapes or structures, such as scales.”

With these constraints, major suit manufacturers such as Speedo and Arena Water Instinct are looking for new ways to improve athlete performance. Team USA (except for Michael Phelps who has launched his own line of competitive swimwear) is swimming in the Speedo Fastskin LZR Racer X. These suits use compression and carbon fibers to enhance muscle activity and connect muscle groups to increase performance from these athletes. The swimmers keep getting better and better with new world records set all the time. It won’t be too long before they overtake the records set in those full body suits.

Bryan Visser
2013-12-04 14.06.58Bryan is a 3rd year graduate student studying DNA replication. He plans 
on making a career for science advocacy working at a museum or in 
Washington, DC. In his free time, Bryan enjoys board games and ballroom 

One thought on “Engineering a Faster Olympic Swimmer

  1. Pingback: Where SHOULD your Olympic sports take place? |

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