It used to be that competitive skaters turned to ice shows after they won their medals and wanted to lay off the training. Not any more. With shows like “Stars on Ice,” which glided into town Saturday night at the Rosemont Horizon, many professional figure skaters are in the same physical condition today as when they trained for the Olympics and the World Championships. The two-hour show included something for everyone. American ice princess Kristi Yamaguchi vamped to Elvis’ “Trouble,” executing flawless jumps, while fellow Olympic gold medalist Scott Hamilton skated all the roles in a whimsical salute to the “Wizard of Oz.”