Ummmmm...Dude....... it's pretty obvious. Go run a few blocks. Just because you don't understand the science behind the reason, doesn't mean it isn't so. You're disputing something that everybody in the running world has known for a very long time. Heck, I'm not really even part of the running world. I just jog on occasion, but find the difference to be immediately noticeable. I had to look it up on the Internet one day, to find the reason why my shin bones were so soar after jogging on concrete.

I'm quite surprised by the lack of tolerance shown by cyclists here. After years of trying to make car drivers show tolerance for us, it seems very hypocritical of us to not show some tolerance for joggers. In creating bicycle lanes, we have unwittingly displaced the joggers, without giving them an appropriate replacement. The joggers were there long before our precious bike lanes.

You may want to consider joggers to be the same as other pedestrians, to somehow justify your right to a small patch of road, but that does not make it so. Joggers achieve speeds greater than other pedestrians, and need to maintain that speed for as long as practical. They just can't get that from a sidewalk, no matter what it's made of. The fact that sidewalks are made of something harmful to joggers just makes this discussion even more ridiculous.