Oh dear, oh dear, oh dear. With less than a minute to go I had to stop as I felt quite light headed. It was a difficult decision to stop running and walk. My head soon cleared and I completed my 5 minute cool down walk.
I probably ran a bit too fast. So this will be chalked up as a training run and I will repeat it in a couple of days time. On the positive side legs felt fine and no tightness in my calf muscles that I felt last time. Stretches must be working.
Onwards and upwards, happy runnings.