GERMANTOWN, TN—The notion of aerobic exercise fleetingly crossed the mind of Memphis-area office manager Theodore Sperling Monday. "There was half an hour to kill before Monday Night Football," Sperling said, "and I thought for a few seconds that maybe I should go for a walk around the block." After raising himself from the couch, however, Sperling instead walked to the kitchen for a leftover pork chop from that evening's dinner and returned to the living room, where he briefly channel-surfed before settling on a Game Show Network rerun of Match Game '75.