Thanks for your input yesterday guys.
I decided as I was feeling fairly rubbish, to have an extra rest day, drink loads of water, get some sleep and see how I felt this morning.
Woke up feeling pretty rubbish, but a bit of ibuprofen, some good strong Yorkshire Tea and a bit of breakfast and I decided to get my running shoes on, go out, and see what happened.
Decided to go for wk3, and also to follow the local streets rather than the cycle paths - strangely, the thought that people can see me spurs me on to try to do better! What do you know - I did it, and it was actually OK! Had to dig in a bit when the last 30 seconds of the last 3 minute run involved a big set of steps over a railway bridge, but I was nearly there by then and I couldn't give up!!
Feeling great now and have definitely earned my pub lunch, once we've been bround the woods with the pooch of course!!
Thanks again everyone, wouldn't have tried it without you!!