I am athletic built and wearing normal L always, in case of doubt one probably also M. The functional shirt of Nebulus unfortunately is not designed for one to athletic build. At the upper body and arms, it spans but very, although everything else fits quite neatly. The pants are okay from the fit. For the price you could expect more probably, however, the material is excellent. It is barely damp and dries in minutes. Very comfortable during exercise in the cold as jogging, skiing, etc. Compared to competitive production of eg Odlo (at least twice as expensive) is then again not all that expensive and offers good comfort.
