I did it! Can't believe I ran 3 mins then 5 mins then 3 and 5 again, a total of 16 minutes! When a few (several actually!) weeks ago I struggled to step up from 60s to 90s!
This program has worked for me so far even if I am taking longer to complete each week.
The evenings are drawing in though. I've been really lucky with lovely sunshine most evenings so far, but not looking forward to switching from grass in the park (unlit) to tarmac on the streets.