Cold Weather
Dress in layers that you can remove as soon as you start to sweat and then put back on as needed.
First, put on a thin layer of synthetic material, such as polypropylene, which draws sweat away from your body. Avoid cotton, which stays wet next to your skin.
Next, add a layer of fleece or wool for insulation. Top this with a waterproof, breathable outer layer.
Don't forget about hydration, as it's just as important during cold weather as it is in the heat. Drink water or sports drinks before, during and after your workout, even if you're not really thirsty.