So I pulled up on this last time, calf cramp/strain. Took some time off and then re ran week 5 - and now just reran week6 1 and 2. Only difference was adding in those stretches as recommended by the good people of this parish. I am aware of very slight/mild twinges but Im hoping for no recurrence. And so far all seems good - lets see how we go now that the running will be consistently 25mins plus...
Fingers crossed. But I think the stretches are the key...