Lynda, I could only manage 4 a few weeks ago..
It's surprising how much the mileage can increase when you don't think about it!!
Once I get through the first 10 minutes (which I always feel like I'm dying in!!), everything doesn't feel so bad...
Have to admit - my little legs start to feel heavy after 35-40 mins though still!!
Drop me a line - I'm happy to meet up for a run and a gossip and a bit of inspiration if you need it Linda!!