Well at long last I've been on a training run - did twice around the common at Southampton in 50 minutes. On the first circuit I had to walk for 4 times ... a few more on the second :) I was running at slightly under 6 minute kilometers (about 9.6 minute miles) when I was running on the first circuit - it varied a bit on the second circuit. I ended up with my "survival" technique - run for 100 paces (left and right foot landing counts as one pace) then 20 walking to recover a bit but keep moving. If I can keep the average speed below 10 minutes per mile then that would make the half marathon I'm doing in September completed in 2 hr 15 min and the full marathon in November (New York Marathon) completed in 4 and a half hours ... now that's something to aim for :) My best marathon time so far is a bit over 6 and a half hours.
I'm not suffering too badly ... slight ache in the upper leg muscles this evening and a blood blister on one toe. I'm going to do a longer one on Sunday morning (also in the Southampton area but a different route) so look out for a puffing runner in green shorts and a "New Forest Marathon" T-shirt.