Well I did it! I was a bit nervous turning up at the start, but I took heart from all the posts I've seen here saying that there are always plenty of walkers and the back-walker to make sure you're not last. I stuck to the programme doing 25 mins running (or just a minute or two more) then walked for about 10 mins, then felt OK to run to the end. It wasn't a great feeling when everyone (about 180 at ours) raced off at the start leaving me right at the back, but it wasn't long before I was picking off a few walkers who had gone off too fast. The really lovely thing was that lots of the strong runners called out 'great work, keep going' type things as they lapped me. That and all the lovely support from the marshals made it really enjoyable. I'll definitely be back!
So now I have a target. 42m 3s including about 10 mins of walking. I'm quite pleased with that as a starting point and am looking forward to knocking minutes off!
Onwards to week 8...