A sleeveless top is one of those classics that you can throw on in summer and winter, for sport or leisure. On hot days, many of us prefer to wear sleeveless tops for running, walking, fitness training or at the beach. When it gets colder outside, we wear them as a baselayer, with a long-sleeved top, softshell or fleece jacket over. Since a sleeveless top sits directly against your skin, it should be made of performance materials (especially for sweaty activities!). Synthetic fibres and merino wool are two fabrics that are often used and are absolutely perfect for sportswear.