Some of the links may be broken, and not all of the content is here yet. A marathon is 26.2 miles. That's a long way to run or walk.
Top athletes can run a marathon in two to three hours.
Expect to take five and a half to eight hours to walk a marathon, depending upon your pace. The key to being able to walk a marathon is proper training, which is why you should try to join a running or walking club with a good program. Here are two good programs for training for a marathon. The first is the one I follow, a modified version of one which I got from Loma Linda Lopers. The second one appeared in Outside Magazine , and is a more accelerated program.