LSky - that is superb advice!!! One mile is good if you are just going to transfer from hotels to trains. When we did our walking safari in Africa, one month before the trip we walked five miles with the backpack packed, on a hot day, with our new boots and specialty socks (that we had just been wearing around the house). It was good to be sure that everything worked, both us and our equipment, as expected. We did this on the advice of the wonderful salesperson who helped us decide on our backpacks. I would NEVER have thought of it on my own.