Well, I wasn’t expecting to post “part 3” of this series up so soon but never mind!
I can see from this that after running to the park (the start is at the bottom left) and we headed clockwise. Heart rate wise green is low, yellow a bit tougher, and red is pushing hard. It was a gentle run until the (now named) “hill of doom” at Broomfield Hill - which is between Robin Hood Gate and Kingston Gate (the red bit in the lower-right part of the map).
When we got back to Ham Gate it was a hard 1k back to the main road, hence the rise in heart rate.
I love the number crunching of all of this stuff so look forward to getting to grips with it further.