This is one of the major benefits of LSD (long, slow, distance) running, especially for people who have (a slight) ADHD (like me).
It allows you to have solitude. I can't sit down and think quietly for an hour, because I .. just can't cope with the lack of stimuli. Running provides some baseline stimulus at least (plus I always set a specific goal, either a distance or a time goal so that I don't give it up), so I just need to survive the first 30 mins and then I get in the flow to some extent. Most of the good work I've done was actually done during long weekend runs -- then I have the week to actually do what I figured out during the run.
It allows you to have solitude. I can't sit down and think quietly for an hour, because I .. just can't cope with the lack of stimuli. Running provides some baseline stimulus at least (plus I always set a specific goal, either a distance or a time goal so that I don't give it up), so I just need to survive the first 30 mins and then I get in the flow to some extent. Most of the good work I've done was actually done during long weekend runs -- then I have the week to actually do what I figured out during the run.