Power Walking has been shown to give many benefits to a lot of people. There is much less stress on the knee's, hip's, shin's,ankles and feet themselves from the constant jarring/pounding from running. And with less wear and tear on the joints and connective tissue. Most noteable, the affects on the lower back and spine. Quite a few sport medical journals suggest, that for a lot of people, Power Walking is an ideal replacement for fat burning, as well as jogging it's self. People tend to forget that focused running is not the same as jogging.
If anyone finds that running or even jogging is not for them, than Power Walking is an effective way to burn calories and insure a better cardio level.. Power Walking is not done at a slow pace, but rather fast with full action from the arm swings. Even as little as 20 minutes a day can improve cardio levels. The usual duration is from 30 to 45 minutes and 3 to 5 times a week. This would include using a tread mill, a track or country roads. Walking on a grade is so much the better. Thought not Power Walking, I ran a lot of steep fire trails in the mountains, when getting in football shape. I would think that you could apply that to Power Walking with very good results, even if you only had hills in your area. Power Walking in deep sand is a very good endurance builder and fat burner. Good Luck.