if you're looking for some exercise the Sodo Arena Sports is a decent field with the new "uber" indoor turf you see now (husky, seahawks stadium). it's pretty convenient to get to if you're coming from downtown or anywhere on the west side. they have all sorts of leagues and levels of play, so dust off them boots and get the blood flowing.
if you're on the east side, their facility in redmond is brand new and VERY nice. 3 indoor fields with a 'club house' for kids bday parties or there's a small bar for a pint after the game.