Thus in October 1946 he wrote to his mother:
My running was quite successful in August.
I won the 1 mile and 1/2 mile at the NPL sports, also the 3 miles club championship and a 3-mile handicap at Motspur Park.
That was the meeting at which all the stars were trying to break records, but in fact were pulling muscles instead.
Being a very humble athlete myself I was able to get away without pulling a muscle.
...The track season is over now, but of course the cross country season will be beginning almost at once.
I think that will suit me rather better, though the dark evenings will mean that my weekday runs will be in the dark.
He was lengthening his distance, and working up to marathon running.
If possible he would make official visits double as training runs.
In particular, he would run the ten miles across west London to Dollis Hill in connection with the plodding development of the ACE delay lines.
Every few months, he would run the rather longer distance of eighteen miles to Guildford, to put Mrs Turing's social imperatives to some constructive use.
It amazed everyone, but he did not care about that.