It was some months back when I read this article in the RunnersWorld on the quality of running surfaces and their comparison. Today, I tried to google my way to locate the same article, and finally found it. It is an interesting read, where the authors rate various running surfaces on a scale of 10. Below in short is the result of the their analysis:
Also, below are references to a couple of articles which talk on the “asphalt” versus “concrete” debate:
Jim Fortner from thefinalsprint.com says:
“… Concrete is a much harder surface than asphalt or macadam. It’s the worst commonly encountered surface that you can run on and should be avoided like the plague. To compare the “hardness” of concrete and asphalt, hit each surface with a hammer and see how it feels to your hand and arm. You will find quite a difference. You will leave a dent in the asphalt, but not in the concrete.”
In terms of risk injury, concrete is rated 2.5 on a scale of 1 to 10 (where 1 is the greatest risk of injury and 10 is the least risk of injury) and asphalt is rated 6?..that’s a significant difference.
Bob Glover in “The Competitive Runner’s Handbook” says, “Concrete used on sidewalks and some roads is the worse surface in terms of shock absorption. If the choice is between concrete and asphalt, take asphalt since it is much more forgiving.”
Another of Jim’s article on this subject can be found here.