The skinny one

Astudy by British psychologists in 32 major cities around the world found that the residents of which city walk the fastest? (Londoners were the 12th fastest.) To find out, solve the puzzle… Add a letter anywhere in each of the boxed-off words to fit the clue, eg, Pigs = WINE+ S = SWINE. Write the added letter in the space provided. Read down the added letters to spell out the prize answer.