Thursday, May 31, 2007

Concrete vs Asphalt: Where do you run?

The scientific literature cannot confirm that running on concrete results in a higher rate of injury, however I did find this report on Environment Canada

"The differences in hardness between asphalt pavements and concrete pavements have been assessed on sections of intercity highway in steady highway speed conditions.[30] In most temperature conditions, there were only small differences between the two pavement types. However, in warm weather, reductions of up to 8% in fuel consumption were measured for concrete versus asphalt surfaces. The effect of the pavement difference at the lower speeds typical of urban driving has not been measured but is probably more pronounced, as urban asphalt pavement has more time to deform."

[30] National Research Council of Canada, Effect of Pavement Surface on Heavy Truck Fuel Consumption, undertaken for the Cement Association of Canada, Ottawa, 1999

Others are less kind when describing concrete-

"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." -JIm Fortner


  1. Jim i think that maybe you should consider looking at the Environmental Benefits of Asphalt vs. Concrete.....

  2. great idea- I will do some research. thanks.

  3. Jim Fortner's comment is of great importance to anyone who runs with hammers on the bottom of their feet. Not so much for those with running shoes.

    It doesn't matter if concrete is eight times or ten times or twenty times harder than asphalt if both of them provide negligible shock absorbtion. That is important is the total shock absorption. Most of that comes from your shoes (including inserts), with some contribution from socks and the bottom of foot. Neither asphalt nor concrete provide any meaningful cushioning.

    One commenter (I think at Jim Fortner's site) did mention the greater friction of concrete which could cause feet to stop more quickly on each step. This effect is probably worth exploring.

    Until I see some scientifically plausible explanation of why asphalt is better than concrete, and that means one that considers total cushioning and not just the probably negligible cushioning of the surface, I'll continue to run run on the concrete sidewalks. There tend to be fewer cars there. And I will continue to drive carefully to avoid the runners and walkers who like to run (or walk) side by side down the middle of the road - to protect their joints while risking their lives.