That was TOUGH! The fast bits were only 4 minutes each, but I found myself wishing they would end, and my legs were aching. I stayed pretty much in the zones today, except the cool down when my HR stayed stubbornly up in zone 3. The heat didn’t help. A faster run today, but at this rate I’m never going to run further than 5k!
But I can’t complain. I saw red kites, heard a buzzard calling, ran along two different rivers and embraced nature (no, not bare arsed naked!). And a man on a bike asked me why I was running slowly. I explained about the heart rate zone training and he said: oh, Fitbit then ...
Back home now, red in the face and sweaty, though I’m still happier running in the heat than the cold.
Edit: just checked my VO2 Max and it’s gone up to 36. I’m 72 years old so that isn’t bad at all! It puts me back in the elite category. And shows the training is helping too.