Is it possible to walk too much?
Yes, but it is not very likely unless an individual has health-related limitations. Just like other types of physical activity, by building the length of time and the intensity of the activity over time, a body becomes accustomed to more walking. For example, many people are not able to comfortably walk one mile. By starting with shorter distances and gradually increasing the distance over time, walking further becomes easier.
If an individual has a health condition that may impact their ability to walk or be physically active he or she should consult their healthcare provider for assistance in thinking about an appropriate training plan.
It is a good idea to consider whether there is a need to plan for water, food, protection from the elements (like sun or rain) and appropriate footwear. The importance of these factors depends on the amount of time that will be spent outside as well as the presence of any extreme weather conditions.
This informational brochure on walking (PDF) from the National Institutes of Health contains a sample walking program that builds mileage each week.
