Base layers are key to regulating your body heat in cold and hot conditions.   You need to match the fabric to the temperature and level of activity for your body to perform optimally. A base layers job is to keep you comfortable during racing through wicking, moisture management and air circulation. This in turn regulates your core body temperature. Base layers use highly technical fabrics to increase blood flow which in-turn increases performance and offsets fatigue. In the summer months you should wear a sleeveless or short sleeve base layer on its own under a race jersey, this will wick sweat away from your skin. Generally there are 4 types of base layer conditions:

1. Warm (those rare +15 C cross race days) - these need a thin wicking sleeveless layer.
2. Cool (days when you need a bit of insulation) - a mid weight short sleeve base layer is ideal.
3. Cold (late fall races where the temp is close to zero) -  a long sleeve thermal layer is ideal or even a good long sleeve wool base.
4. Extreme (those windy below zero races) - you need a good long sleeve base layer with a windproof panel under your skinsuit to survive these.

We stock base layers from these fine companies: Craft, Descente, Hincapie and Assos.