well sure no wonder you get high heart rates there completely indoors with a tiny fan! My turbo sessions are in the garage at 6am (usually you can see your breath) with doors open and fan on! Quite nice doing them in the morning as you don't feel 'hyped' when trying to sleep and you can watch the sunlight get brighter etc. the other day I had a fox do a double take and peek into the garage run away and then slowly come back for a second look, bet he was confused
Maybe I'll try harder next time but I'm basing my zones on my max hr from 2 years ago, I assume it decreases with age? by how much per year, not much I see from the web. Recently I found it hard to get my heart rate up too high, before on the turbo I could get to 195 bpm but yesterday I barely went over 180 when out of the saddle. This was the second turbo day in a row as I am doing them Tuesday and Wednesday morning, that might make a difference. I will have to rejig my sessions anyway to fit around CP from next week.