In another existence I ride a fixed wheel bicycle around London. This has no gears and no free wheel. If The bike is moving, you are peddaling. At first this is really tiring. It is because you resist. After a few weeks you learn to yield and go with it. Your legs become the freewheel and you flow without thinking about it.
As I cross Paternoster Square at the end of my run, I realise I am freewheeling. Moving with grace and in harmony but without effort, and yet relentless. This is where you would need to be for the marathon I note.
The rest of the run was The Charing Cross footbridge route I did the other day but backwards. Across Blackfriars Bridge, down The South side of the Embankment, Charing Cross Footbridge, North Side of The Embankment, Paternoster Square.
31 minutes probably around 5.5 km