This morning I covered ~4 miles by feet, of which only 1.25 mile was running. In addition to being easier on my knee, the slower pace of walking allows me to enjoy the world around me in a new and different way, but it takes *forever* to cover the distance.
When I got home, I decided to do a little research about the benefits/disadvantages of running vs. walking. This is what I've discovered:
1) From a calories burned perspective, logging miles makes a lot of sense. It doesn't matter if you run a mile or walk a mile, it takes the same energy either way. But since running is faster, walking requires a larger time investment to burn an equivalent number of calories. It's doable, just takes longer.
2) Walking does help with cardio fitness, but not as much as running. That's because normal walking doesn't usually raise one's heart rate to the optimal training zone. Brisk walking and/or hilly terrain, however, may help.
3) Running has 3-4 times the impact on your bones and joints than walking. That means running has a higher risk of injury. It's also why it bothers my knee more. But on the flip side, the higher stress on the body from running has a bigger benefit toward building/maintaining bone density.
After digesting all that I've learned today, I'm beginning to think that a good compromise may be either a structured easy run/walk (Galloway-style) or race-walking (which I'm really not too interested in).
And with that, I'm off to learn more about the Galloway method...