The fabric is made in which this T-shirt has obviously a special structure because it is both very soft, elastic, warm and light. As soon as one puts it, it feels like a real well-being of the nature of the fabric but also thanks to its cut which makes it perfectly suited to your forms. It is supposed to be worn for sports but is also an ideal underwear. I did not test it by going to run out because it is too cold at this time, but I made a half-hour gym wearing it and found myself very comfortable: not too hot, not too cold. I enjoyed it so much as I still had two Christmas gifts to make for women in my family that I will see in January, so I've ordered two!