I slowed down and my heart rate didn't care

The pace changed. The effort didn't.

Before I started running, I had already read about Zone 2, conversational pace, and heart-rate drift. My brain collected the vocabulary much faster than my legs collected the habit.

The fuller story of those early runs belongs in another note. The short version is enough here: my pace changed from 7'07"/km to 7'40"/km, while my average heart rate moved from 160 bpm to 159. The July 15 run was still hard overall, and I finished drenched, even though one short stretch had felt easier.

I had followed the most obvious instruction and slowed down. My body seemed unimpressed.

One kilometre changed the experiment

On August 9, I changed the experiment. I stopped trying to make a longer run work and used one kilometre as my adaptation distance. These were continuous runs without walking, usually at 8'40"–9'20"/km. One kilometre was short enough for me to hold my attention and stay with the rhythm.

By August 22, those short runs added up to 11.6 kilometres. My heart rate was usually around 130–135 bpm, and cadence stayed around 158–160 spm. The shorter distance and slower pace account for part of the lower heart rate. For the first time, the run felt small enough to repeat.

The 59 percent I wanted to move

Health Run calculates the easy-running share from the valid running time I spend in the easier heart-rate zones. It gives me one number for how much of the run stayed at the effort I was aiming for.

After one of these short runs, I opened my cadence profile. The latest run showed an average cadence of 155 spm, inside my 154–160 target range, and an easy-running share of 59 percent. The five points on the chart were 62, 40, 43, 16, and 59 percent. It wasn't a smooth line.

The 59 percent was the number I cared about. The screen told me to keep the rhythm stable for a few more runs before raising the target. That matched what I wanted: make the same kilometre cost me less, then think about making it longer.

One kilometre is where I am

The one-kilometre runs still require effort. I don't float through them. I can hold a steadier pace, spend more of the run with my heart rate in the 130s, and go out again without needing thirteen days of psychological preparation.

For the next few runs, I'm keeping the distance where it is and watching whether that 59 percent holds. Then I can start adding distance.