To come back to this, I too would like to know the thoughts of those with more experience on this. It doesn't feel wrong to me. It gets my heart rate up in a way that I can control, so it seems useful from that point of view. I can push harder, or ease up as I need to. And nothing else I currently do gives my calf muscles as good a workout - I can really feel that; well, since recovering from the injury anyway! And I'm still not sure I can get out and manage a worthwhile distance running properly - even round the block - so it seems to me to be a good way to build up to that. I know jobo's view, but the fact that I can push into 'sprints' when I want to at least partially gets round that. Bearing in mind that I am just starting out, and want to get to running outside anyway, is there any harm in jogging on the spot? Apart from that injury from doing too much too soon, I can't feel any adverse effects.