Workout clothing has come a long way from the typical T-shirt and shorts. Clothing and fabric companies have poured vast amounts of time and money into the research and development of ideal fabrics to keep the wearer cool and dry. The demand for quality workout clothing has generated many choices but personal preference may ultimately still be the deciding factor.
The active concept behind moisture wicking athletic wear is the fabric’s ability to draw moisture up and away from the skin. The fabric promotes a capillary action that draws moisture up into the fibers of the fabric and off the skin's surface. However, the fabric’s ability to cool comes more from how quickly the water evaporates from the fabric once it has been drawn away from the skin.
Cotton has been the go-to fabric for athletic wear before the concept of moisture wicking became popular. The fibers in cotton still absorb moisture but are slow to dry. This slows the cooling effect, as the saturated fibers impede breathability and trap heat and more moisture against the body.
Polyester and Synthetics
The majority of moisture wicking athletic wear is constructed of microfiber. Microfibers are synthetic fibers measuring less than one Decitex per filament. The micro nature of the fibers allows a greater number of fibers over a surface area, yielding more capillary action in the same amount of space. Microfibers are commonly made of polyester, nylon, kevlar and polyurethane.
Polyester constitutes the most popular material used in microfiber sportswear. The moisture wicking capabilities of the blend are based on the weave of the polyester fibers. A tighter woven polyester fiber draws more moisture away from the skin while allowing active evaporation of the moisture at the same time.
Most microfiber clothing is a blend of fibers such as polyester, Lycra, spandex and cotton. Most often, the additional fibers such as Lycra and spandex function more for elasticity than for breathability. Where synthetics are concerned, keeping cool may best be achieved with clothes incorporating a blend that includes predominately polyester in conjunction with other materials.
Though not commonly associated with active wear, wool is a natural fiber that boasts highly effective wicking properties. Many sports activities require insulation and warmth as well as wicking properties to keep the user dry. Wool can be ideal for outdoor activity in cooler weather. Synthetics continue to wick even in cold weather but can remain damp against the skin as moisture evaporates slower at cooler temperatures. Wool continues to wick moisture while still holding warmth against the skin even while damp.
Microfiber athletic wear comes in a multitude of styles and designs. A high percentage of polyester in the blend will ensure a better wicking and cooling effect, but the consistency and feel of the fabric may be a deciding factor individual to each user. Some prefer a higher percentage of compression or skin-tight layers to speed evaporation of moisture, while others may prefer a looser fit or a lighter fabric. The type of activity can also dictate the choice of synthetics versus wool or the fit of the garment.
- USGS.gov: Capillary Action
- Textile Terms and Definitions, 11th Edition: The Textile Institute
- Study on the Wicking Properties of Polyester Filament Yarns: Ni Wang, et. al. Fibers and Polymers, Volume 9, No 1, 2008
- WildSnow.com: Synthetics vs Wool Backcountry Clothing
Jullie Chung writes regularly for various websites. She is a nationally certified fitness trainer and performance enhancement specialist through the National Academy of Sports Medicine and trains regularly in yoga, flatwater kayaking, boxing and mixed martial arts. An avid outdoor fan, she regularly hikes, climbs and trail runs.