At the end of the year I purchased a weighted vest to use with my clients that I train at home. I have used it a few times myself and I can tell you it makes a difference. My vest can be adjusted meaning I can add the weights gradually. Last week I found an article about walking and the question was asked "Does Wearing a Weighted Vest While Walking Burn More Calories?" My take away from the article addressed the issue of those that cannot walk briskly. Adding a weighted vest of 10% of the body weight can produce a similar intensity of those walking faster. Some of my friends walk outside and have maxed their walking speed. I can walk 4.0-4.2 and that's about it. So if I want more intensity, I need hills or a weighted vest. To be honest, when I use the vest myself I do it with the hopes of improving bone density. I am not suggesting that you run out and buy one. If you have back or hip issues to start with it might be a bad idea. I'm just passing on some information that serves as food for thought. If you are interested, do some research.
resource: "Walking: The Latest Research" by Len Kravitz,PhD