If you’ve ever been in a sweaty cardio class in a cotton t-shirt instead of your studio kit, you’ll undoubtedly be aware that clothing designed for exercise is much more absorbent than your civvies. What makes all the difference is the fabric’s ability to wick.
At its most simple, wicking is the movement of moisture by capillary action: a kitchen towel wicks up a spill, a mop wicks moisture up from the floor and it is this action that makes molten wax move up the wick of a candle – hence the name. When related to clothing, wicking generally describes the movement of sweat away from the body. To cool itself, the body produces sweat which sits on the skin’s surface until it is evaporated by heat drawn from within. As heat moves out of the body, body temperature lowers.
This is all well and good if the skin is uncovered, but less comfortable if there’s a layer of clothing on top that becomes saturated with cold, clammy sweat which then rests against the skin. Add to this the chaffing which can occur when you exercise in damp gear and it becomes clear why finding wicking textiles is so important.
In textile structures, the spaces between the fibres effectively form tubes or capillaries. A textile with narrower spaces between adjacent fibres tends to wick moisture away from its source better than a textile with wider spaces. However, capillary action ceases when all parts of a garment are equally wet, as the liquid has nowhere to travel to.1 “When a fabric wicks, it moves the moisture away from the skin and holds it in the fibres of the fabric or moves it to the outer layer furthest away from the skin,” says Dr Mark Taylor, research fellow at University of Leeds School of Design. “Fabrics that manage moisture effectively don’t become saturated as quickly as non-wicking fabrics, so this is why they are more comfortable,” says Taylor.
Initially born out of the burgeoning post-war man-made textile industry, the development of wicking technology and moisture management fabrics gained ground in the 1980s. Although sportswear is now a highly profitable mainstay of the industry, it was originally outward-bound activities like mountaineering, where efficient regulation of body temperature is crucial, which created the initial impetus to develop these fabrics.
The first company to develop a moisture management fabric was Damart in 1953; however, it was the introduction of a DuPont product in 1986 that really kick-started the industry. Since then, sportswear companies including K-Swiss, Reebok and Nike have all developed their own wicking technology, while X-Bionic has worked on an alternative moisture management fabric that uses sweat to enable better cooling. Most of the fabrics being developed are derivatives of petroleum.
So which one is best? “If a fabric has intrinsic wicking properties, the effect will be long lasting. However, some fabrics gain their wicking abilities from a special coating which will wear off after a number of washes,” says Taylor. He also points out that various natural fibres like wool can also manage moisture, which is why merino wool is popular as a base layer. The most effective garments are those that are tight fitting to allow maximum contact between fabric and skin.
Says Taylor, “The knock-on effect of wearing clothes that keep you dry and comfortable is a significant improvement in your performance.”
This feature was first printed in the December/January 2012 issue of Fitpro magazine.
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