How Does Hair Slow Down Swimmers?

When watching competitive swimming events, such as the Olympics, you may notice that the bodies of the male competitors are clean-shaven. Also apparent is that competitors of both genders keep their hair trapped under latex caps. This is because any exposed hair left on the body slows down the speed of swimming. The reasons are based in science.

  1. Air Bubbles

    • When swimming with an unshaven body or exposed scalp, hundreds of air bubbles cling onto each strand of hair, creating drag that slows you down. As you may expect, the more hair you have exposed in the water, the more air bubbles will cling, and the greater resistance you will experience when swimming. Additionally, wet hair is heavy, and more weight makes for slower speeds.

    Speed

    • The speed at which humans swim tops about 5 miles per hour, with a record-setting 50 meters in 21.3 seconds. When you swim with exposed hair, it slows down your overall speed by a few tenths of a second per lap, though the precise time lost per lap is not known. Losing this time in your laps can translate into losing the advantage in a competition.

    Combating Resistance

    • To combat resistance, many swimmers shave all hair from their bodies, including the arms, legs, back and chest. Additionally, swimming caps not only keep the hair from causing drag but will protect it from the chemicals found in the water, like chlorine. Some male swimmers elect to completely shave their heads, as well, eliminating any possibility of hair slowing them down.

    Alternative Methods

    • A male swimmer may not feel comfortable shaving his entire body or wearing a Speedo. As an alternative method, he may elect to wear a bodysuit. Its design can include ridges and surface pockets to reduce drag and resistance. The Fédération Internationale de Natation, the international governing body of swimming, decided on rules regarding wearing bodysuits during competitions. The suits may not be more than 1 millimeter thick, may not extend beyond the shoulders, cannot be tailored to the wearer, and the swimmer may not don more than one at a time.