I started speed walking about one year ago. I finished my first 10k this jan. I am training for my half-marathon at the end of this year and last week I was able to run three days in a row, which was unthinkable about a year ago, I am not overweight, but speed walking or light jogging used to cause me a hell of a lot of pain and it used to take me a lot of time to recover, sometime more than one week from light jogging.

I do weight training too, but running is a totally different feeling, before I used to force myself to go for runs but now it takes a lot to stop me to go for a run. Its hard to explain, its like I am addicted to it, even though its still painful, but I am recovering much much faster.

I too recommend everyone to give running a try, if you can through the initial hurdle, I don't think you will ever regret it.

Just today, I also finished reading "born to run", while I understand that there are exaggerations in the story to make it more interesting for the readers, and science of "born to run" is still 'up there' and perhaps debatable depending on who you ask, its still one of the best book I have read. Highly recommended to read.