Undergarments

Just as other outdoor sports require participants to wear layers under their outer garments, cyclists should wear ‘base’ layers under their jerseys. This applies to cooler and warmer months as it’s not simply about staying warm, although that is a consideration. The main reason for wearing base layers is due to the effect wind has on sweat left on the skin.

If you leave sweat on the skin and it comes into contact with wind (even through a jersey) which is unavoidable while cycling, a ‘chill’ is created on the surface of the skin, similar to the effect on a bottle that is run under water and placed in the fridge. The cooling is sudden, and any sudden changes in body temperature should be avoided.

A base layer assists in this by removing sweat from the surface of the skin and placing it on the outside of the undergarment. When the wind hits this the chill is minimised and any changes to body temperature are subtle and moderate. In warmer weather this allows a rider to cool down as the moisture is touched by the wind while a rider moves. As they are only wearing a jersey, the wind can penetrate through to the undergarment and assist the rider in controlling their body temperature. In winter the chill doesn’t take place because moisture is taken off the skin and airflow to the base layer is minimised due to windstopping outer garments (which will be discussed later).

There are varying versions of undershirts, designed for different seasons and constructed using a variety of fabrics. Those aimed at summer riding will feature ventilated materials while those for cooler periods will be made from thicker fabric that is better able to retain heat while moving sweat.