What do Polish people typically look like?

My grandparents are Polish American (they immigrated from Poland as kids in the '20s.) Because I only saw them in very old age and their grandkids (including myself) are mixed ancestry. What do Polish people typically look like? Like certain features, complexions, body shapes, etc. I have also heard that Poles are really athletic, strong/muscular. And also, is it possible for me to have some Russian or Czech or some other ethnic group in there too?