My heart rate was a lot less variable today, probably because I had eaten before.
Completed 3.49 km today in the 30 minutes at average heart rate of 149. Average pace of 8:36 minutes per km.
I should also point out that where I run is hilly, which undoubtedly affects the time. For example, today I gained 70 metres and lost 68 metres. The hills are around 15 metres high and there’s roughly 2 per km.