Running alone with no music turns into a conversation with yourself by mile two.

Repetitive movement with no input starts producing thoughts whether you asked for them or not. The first stretch is mostly complaining about the run. After that your head runs out of surface material and moves to whatever you have been putting off thinking about, which is why that kind of run often ends in a decision you were not trying to make.

Leave the headphones behind once this week, on a run or a walk if running is not your thing. Go past the complaining phase. The useful part begins right after the boredom does.