She always pulls at the leash a bit and wants to be a little ahead of me. On the empty road down to the swim and tennis club I decided to see if I could go as fast as her. I steadily accelerated and eventually she was following me! I could only maintain that speed for about ten seconds and probably haven't run that fast in 20 years.
I put a few more sprints in that 2 mile morning run but could not outrun her--so either she just wasn't tired or just not quite as tired as I was. I am tempted to take her for a longer run, just to see what she can do. I am reluctant because I don't want her to injure herself and I don't want to be miles from home when she suddenly refuses to continue. I would end up having to carry her home. She is only 17 lbs, but she might wriggle, so it could be pretty unpleasant.