Dispatches from the Staff
2:05 pm | Monday, Dec 3rd 2007
Layering 101
There is a misconception about cold weather clothing that rears its head ever year with the first signs of cold winds. The misconception is that a bigger jacket equals more warmth. To better understand the fallacy of this misconception, it might help to imagine your active wear in 3 layers. The important thing to remember is that if your heart beat is elevated, you generate core heat and sweat. To stay warm and healthy, you must layer your clothing in a way which best moves moisture away from your body while conserving this heat. The first layer is your base layer because it is the closest to your skin. If you intend to do something active outside like running, cycling, or skiing, this layer should be fairly thin and snug to your body. Silk, polyester, or wool garments are good options because each fabric evenly absorbs and lifts moister away form your body. Your body's heat will continue to drive perspiration away from the base layer and into the 2nd layer, or warmth layer. This layer has two functions. It continues to move moisture away from the body and traps heat. Polyester and fleece are the two most popular materials, but lately wool has reemerged as a contender. Furthermore, these materials are not compromised when wet but continue to trap your body's heat. Down, on the other hand, is a poor choice as an active warmth layer. It flattens when wet and fails to trap heat. The thickness of the warmth layer depends on your activity and duration. For example, riding a bike for two hours elevates core temperature for the duration of the ride, thus you can use a thinner layer. Skiing, on the other hand needs a thicker layer because it alternates between an elevated core temperature on the slopes and periods of losing that heat while waiting for the lift. This brings us to the final layer. The outer layer protects from environmental conditions like rain, snow and wind. A good outer layer should be water resistant and breathable. A waterproof jacket that is not breathable, like the bright yellow rain-slickers our parents sent us off to school in, do a great job of keeping moister out, but they also keep moisture in. Remember, the idea behind layering is to utilize body heat and move moisture away from the body. Rain-slickers only trap moisture and restricts the body's movement. Finally, a good outer layer jacket should have zippers under the armpits. This allows you to vent moisture without having to take a layer off and lose heat. In a good layering wardrobe, the base layer and outer layer change little if any, while the warmth layer changes depending on the season and activity. For example, as a minimalist I run in the summer with a short sleeve or long sleeve synthetic base, add a thin fleece/windstop vest for colder weather cycling, and finally a thicker fleece pullover for hiking or camping. Don't get me wrong, the Michelin Man 'look' works for reenacting moves from the WWF, but for outdoor activities and protection from the elements the big jacket misconception has outlived its time.