- Base Layer: The purpose of this layer is to wick moisture/perspiration and keep it away from your skin. This keeps you warm and dry. For best results, choose a tight-fitting wicking material such as polypropylene, silk, polyester, thinsulate, cool max or dry fit – all good choices. These materials will pull the moisture away from your body and keep you dry. Avoid cotton because it traps moisture and your body has to work hard to dry the cotton and keep you warm. Base layers come in various weights (lightweight, midweight and heavyweight). Select a weight based upon the outside temperature and your activity level. The lighter weight is better at wicking; the heavyweight provides more insulation.
- Mid Layer: This layer provides more insulation and its function is to pull the moisture from the base layer out to the outer-layer. As the fall progresses into winter, you will need to add this layer into your dressing, especially if you are going to be doing lower-level activities for a long period of time. The amount of Insulation desired is also dependent on your personal preference: if you get hot quickly you may still want to stick with a lighter insulation layer. The mid layer should be a bit loser then the base layer but it still needs to maintain contact with the base layer. Common materials for a mid layer are down, polyester, fleece, and synthetic materials. Many mid layers may have added ventilation for when you warm up on your adventure. Things like pit zips, long zippers, adjustable collars or cuffs provide a way to moderate your body temperature throughout your workout.
- Outer layer: This layer provides a critical wind block, and also allows moisture to escape. Typical outer layers include shells made of Gore-tex. There again this layer should also have special features such as pit zips and adjustable collars and cuffs.
As we layer our upper body we tend to forget that that same rules apply for our legs. As your fitness level improves, less blood will flow to the legs, so for the longevity and productivity of the activity make sure you keep those legs warm with appropriate clothing. Layers of tights are strongly recommended.