I did it...I actually did it!!
Even though I had a little 'wobble' before I set out - perhaps I needed another day's rest, will the old knee hold out? not sure if today will be a good day etc... Banished the negative and switched to my 'think like an Olympian' mantra. Set off and relaxed, first 5 minutes seemed hard...kept going...half way through (already!!) and still going strong(ish)...round and round the field..two minutes left...dig deep...done!
Surprisingly I didn't collapse in a heap but actually ran on for a few seconds more, felt like punching the air but managed to contain myself as a jaunty lycra clad chap had just overtaken me and I didn't want to scare him!!
It may have taken me months to get to this point but success feels all the sweeter for the earlier challenges!