MCCALL, ID—Determined to rebound from his 2000 election defeat, Al Gore has sequestered himself in a remote mountain cabin to train for his 2004 rematch with George W. Bush. "Gotta get in shape," said Gore, running up a hill with a log strapped to his back. "Gonna beat him this time." Gore, who is almost back down to his campaigning weight of 245, then worked on his debate reflexes by chasing chickens around a pen.