That's fascinating Malcs, and very good news to boot.
I eschewed the work curry night then, and went to our club night, it was a simple triangular route, and I wanted to do it to gauge any improvement. It was a good session, but my legs hurt all over now but My instinct is that it isn't something that will be a problem.
firstsession was 1.8 miles/7.26mm uphill, then 1.6m at 6.52 ( wind behind) then 2.2 at8mm. big improvement over last time, and again the feeling of having an engine if that makes sense.
Rest tonorrow, then helping elder son move house, so lsr probably Sunday.