Today, I did the first one for week 7. Five minute walk, 25 minute jog, 5 minute walk. My legs were a bit tired on and off throughout, but this was OK and doable. Total: 3.5 km. Looking at my data from my heart rate monitor afterwards, if I added another 5 minute jog at the end at about the same rate, that would mean I would add another 0.5 km if I jogged 5 more minutes, so that means I would do about 4 km total if at today's pace by the end of the 9 weeks. That's OK for now. I'm just trying to complete these without always pushing myself to do a lot more distance, and without pushing my heart rate and tiredness too high.
It is defintely helpful to have jogging partners that love exercise and these walk-jogs way more than I do ... my 3 dogs. 
Varying the location often is also helping. We have so many nice city parks and bike paths here. I just went to a nice park that I hadn't been to for quite a while, jogging along the river. The paved pathway had been almost completely cleared off of snow and ice, so the footing was perfect. Some deer near the pathway early in the walk added to the excitement for the dogs... and gave my upper body a bit more of a workout, holding onto my dogs' leashes.
- Lisa