I admire your passive aggressiveness in your second paragraph, but I think you've misunderstood my point. I've said repeatedly that any exercise is good exercise. Not sure how else I can be clear on that. I'm not saying, implying or otherwise that people shouldn't try to make a positive change. I absolutely LOVE hearing about it and seeing it. Not to get sidetracked, but I as much as I am not a fan of "reality TV", I used to love Biggest Loser because I loved the stories of people making that change. I wish the show would come back. I wholeheartedly agree that the "starting point" is very much to be considered. I couldn't agree more. Just like people don't get out of shape overnight, you can't get into shape overnight. It's one step at a time (literally), and one day at a time.
As far as WDW goes, my opinion, and you're welcome to disagree, is that if you're really out of shape taking a short walk for a little while before a WDW trip really isn't going to do a lot. A 2 mile walk might take 30 minutes, then you're done. A day at WDW may involve 8 miles of walking over a 7 hour period. When you're not walking, you may be standing up, so that has to be considered too. So I feel it's apples and oranges. Again, does any physical exercise help? Not sure how else to be as clear as I can be...yes, yes, yes, yes, yes. Do it, do it, do it, do it, do it. However, I just don't think it's realistic to expect that to make a huge difference in a week long WDW trip. You're welcome to disagree. But a thousand times yes, make a positive change, if you're "out of shape", any time is a good time to start.
How do you prepare for WDW? I don't really know there is a true way to totally prepare. Walking 8 miles per day and standing that long for days on end is something most of us (myself included) don't do on a regular basis. So unless it's your normal lifestyle, I think it's going to be tough on most people. I know it kicks my butt.