I'm in my early 50's, and we visit WDW at least once a year. In order to walk the 10+ miles per day it takes to visit from morning to evening without having to take a break several times a day, it's important to have the right shoes, be in shape, and drink lots of water.
I purchase running shoes, not regular sneakers. Be prepared to pay well more than the $30.00 sneakers you get at
Walmart. You'll be glad you did. Buy the Smartfeet insoles, also (another 35 dollars), if you have arch issues. Have the salesperson at the athletic store fit you correctly. If you go to a store that doesn't have a salesperson to fit your shoes...you're not going to be buying
good running shoes.
Drink water. All day long. Yes, you'll have to stop and pee, but better that than laying there waiting for an ambulance while you cramp up and dehydrate!! All of my
DDP snacks are used up with water, and I get water with every meal. Even if you don't mind the heat, it's a different climate from what most of us are used to, and dehydration can ruin your week, if you don't get enough water. Another bonus is that by drinking plenty of water, you won't overeat.
Have some salt (but not too much). The heat will cause you to lose electrolytes, so if you typically don't eat any salt, you might be able to add a bit to your diet.
Don't lug around a lot of needless crap. I either carry a small fanny pack, or a larger lanyard with a pouch around my neck for my Key to the World, some cash and my cell phone. I don't bother with a camera, and carry my PhotoPass card...for those special photos. I already have 5 million photos of WDW from my past trips!
We often go back to the resort in the middle of the day for a quick dip in the pool. It's refreshing, and floating around in the water gives your body a quick rest.
Make sure you bring ibuprofen, or some other anti-inflammatory medication for those aching legs. I walk a lot during my day, but a day at WDW is like a marathon, and I still get achy by bedtime. Often I take Advil PM, which has the added benefit of a sleep aid.
I don't mind the heat, in fact my motto is "the hotter, the better" I see a lot of poor suffering folks at WDW who are wearing way too many clothes. Jeans are just too hot!! Use lots of sunscreen instead of long sleeves. I wear hiking shorts. They breathe, and won't chafe the insides of your legs. I also wear the sleeveless hiking tank tops, which are very comfortable.
I hope you have a wonderful time at WDW, and that you're feet stay happy!