Ironic that Bush has time to excercise

Exercise is important for both physical and mental health. I know this because I haven't had a normal routine of it for 2 years simply because I've been too busy. So why is it that U.S. Presidents seem to find the time to exercise so consistently once they get into office. And I mean consistently! Bush is in China and the clips we get are of his misplaced bravado on a bike, riding with the locals. Prior to obtaining the presidency most do not (or am i wrong?). Of course, every president comes out of office with significantly grayer hair so I doubt they find it that relaxing.

On another note... how far away is 2008? You know, in every other democratic nation if a leaders approval rating drops below 40% the opposition moves to dissolve the current government to give way to early elections. Why can't this happen in the US?