I am pleased to report that I did it. I was dreading it and even took 2 days rest from my last run (WK1-R3) because I was feeling a little stiff around the knees and I have had problems in my past with dislocations of the knee. It was probably a wise decision I think as I am feeling pretty good all round right now.
I was unsure how well I would make the transition from 60 sec run to a 90 sec one but I didn't find it any more difficult than week 1's runs. I did feel tired at the end but I am in a bit of a high that I seem to be sticking with it.
I took someones recommendation of making sure I had something to eat and drink before my run and it worked - no dizziness this time.
I have also lost a few pounds in weight too as a bonus as I am carrying about 7 pounds too much at the moment. I am not worrying about that though as I am pretty sure it will melt away gradually.
I find when I have made the decision to run I begin to phsyc myself up for it.
I listened to my own music. It's Latin American so a great tempo to run to I find.
Having a little rest now and a drink.
Thanks for your help and support.