content: I read ChiRunning in Sep 09. It took me 2-3 wks to get the form right while running. I've been ChiRunning since.It's not effortless - my heart rate meter tells me so - though it does feel effortless for a whole minute or two doing medium sprints. I now run 4x a week, an hour or two each time. This is something I'd never been able to do in the past because my knees always started giving problems and I'd have to train on an elliptical afterwards. The knees are fine now. I'm sure Danny wouldn't recommend it, but you can even run on a bad knee with this technique - I ran 10k on a poor knee without much loss of speed.My timing has also improved, though not as much as I'd hoped or expected (hence 4 stars).Enjoy running? You should give it a go.