Our new A-Thermic sports underwear line is another technical and highly sophisticated innovation that offers significant benefits for you as an athlete. You can feel how extraordinarily light A-Thermic underwear is as soon as you touch it and you can feel how warm it is as soon as you slip into it. Discover the secret of the special Active Warming technology created by our fabric experts. The thermal capacity of 100 grams of this yarn is 40% higher than, for example, our Active Warm yarn. This is made possible by integrating specific carbon particles into the yarn used in knitting our A-Thermic sports underwear.