I can't quite believe it but I did it! I'll be honest, I'm not exactly going fast ... but I am managing to control my bouncing up and down and breathing. I felt better after last night's run than any of the others. My legs did tighten a lot during the first of the 3 minute runs but I decided to concentrate on the view instead of my legs and that seemed to do the trick. I'm almost looking forward to my next run tomorrow evening.
Thanks to everyone for their support and good advice. Unlacing my running shoes is helping with the pins and needles (I may need to go down another notch) and I'm worrying less about what other people think as they see me 'jog' by all red faced and sweaty.