A composition contains a thermoplastic polyurethane (TPU-1), obtained or obtainable by reaction of an isocyanate composition (IZ) containing MDI with a polyol composition (PZ), and hollow glass microspheres. The polyol composition (PZ) contains at least one polyol (P1) selected from polytetrahydrofurans having an average molecular weight Mn in the range from 900 to 2,000 g/mol. The polyol composition (PZ) also contains a chain extender (KV1), selected from 1,2-ethandiol, 1,3-propanediol, 1,4-butanediol and 1,6-hexanediol. Ski shoes, preferably ski boots, particularly preferably the outer shell of a ski boot, can be based on such a thermoplastic polyurethane. Corresponding processes can be used for producing ski shoes.