Traü will stretch to fit so if your waist size is in the range above, they will stretch to fit you.
They run slightly bigger because of the stretch. A person that's about 6', 190 lbs. will comfortably fit into a Medium.
Note: there is a natural pilling that will occur with the material. That's normal.
Traü are like your flannel sheets. They will wear in and get more comfortable with time...that is until you need a new pair!
To reduce pilling, turn your Traü inside out when you wash them, that should reduce the friction with other materials in the wash.