I knew it would be harder, but I've already done 20 mins so I know I can do 25. I also chose a new route to make it a bit more interesting. Things were going reasonably well until I spotted a large playing field which seemed like a good idea and would make a change from pounding the pavements.
The one thing that didn't occur for some reason (Why not?! We've had floods here!) is that it would be very soggy, plus it's a rugby pitch... I managed to find some firmer ground along one side but as I ran further round it turned into a quagmire. I was really struggling, slipping and sinking and it sapped every ounce of energy. I tried forcing myself on but it was just too much and I was concerned I might hurt myself so I have to admit that I stopped.
There was a gate just a few yards away and as I walked up to it I realised that it led onto a path that took me back to my route - so off I went again, and found the running was fine, so much so that when Laura said 60secs left and to try and up the pace, I did.
I'm pretty sure I only walked for about 30 secs in the end - just long enough to get up to and through the gate so I'm trying not to feel too despondent and I'll keep telling myself that the effort of running through mud and the extra pace at the end made up for it!