The leg warmers are an item of the cycle gear whose function is to totally or partially cover the legs. They're worn under the cycling pants from the crotch to the ankle, shin or knee in function of their length and design.
Generally the leg warmers are used mid-season to substitute long cycling pants for short, when the former are too much for the rest of the route, once we've reached a suitable temperature for the legs.
Just like the arm warmers their tight, elastic fit provides compression suitable for comfortable pedalling. The wide variety of latest generation fabrics and technologies lets us choose between different types of leg warmers depending on the weather conditions. Another sought after detail for maximum comfort in cycle leg warmers is that they have silicone inside the ends to avoid slippage due to movement, sweat or from rubbing against the cycling pants or the sock. In spite of the various sizes, the leg volume is different for each rider, thus the silicone trim improves the hold and rigidity of this garment whilst pedalling.
According to the modality, the leg warmers can be replaced by high and compressive socks. In this case, their main function is compression in order to provide a better recovery of the leg muscles.