Confidence builder - speed walking

So nursing a sore back and recovering calf muscle, I decided to give power-walking a go. Here's what I learnt:

1. I'm a slower runner than I thought
2. I'm a faster speed walker than I thought
3. Speed walking feels like it 'bashes' my calf muscle a lot less.

So last Thursday I walked 8km, no problem. Saturday 9km, Sunday 10km. All very good and easy. My fast walking pace? A little under 8 mins/km versus a little under 7 mins/km for when I'm jogging.

Talking on the subject with a few others, I've learnt about people who intentionally employ a "run-walk" approach to long distance running. The idea is that while you're jogging you're giving your walking muscles and break, and vice versa. I heard that some people can "run" a marathon using a run-walk technique in around the same time - and perhaps with less strain and risk of injury - than if they were to non-stop run the same.

Historically I've associated walking on a fun run as a cop out. I've now revised my opinion on this!