I don't think asphalt will give under the weight of a person any more than concrete. Unless the surface absorbs a significant amount of shock the surface would make no difference.

I agree! We need to get the joggers off of the streets and back on the sidewalks where they belong. I can picture all sorts of devices being tested for their relative desity and subsequently dropped on the two surfaces in a lab. Clearly all of the layers betwen the human knee joint and the ground have much more impact on the impact than the man-made surface one runs on.

I agree. I think the Mythbusters should take this one on. No doubt there is a measurable difference in elasticity between asphalt and concrete, but I really doubt that someone wearing decent running shoes would ever notice a difference physiologically even over a lifetime of regular jogging.

I would love to see this one settled one way or another. I'm a runner and have been told not to run on concrete by all sorts of people, but I just find it hard to imagine a that sub-200 pound person wearing well cushioned shoes would come down with enough force to cause pavement to give.

Most runners seem to believe that there is a big difference. In fact, there's almost always a debate going on somewhere on the Runners World forums.

They should test asphalt and concrete along with dirt trails and gravel roads. Probably should throw in the nice rubberized track surfaces too since that would almost certainly give some.

quote:

Originally posted by khamlerd:
I agree. I think the Mythbusters should take this one on. No doubt there is a measurable difference in elasticity between asphalt and concrete, but I really doubt that someone wearing decent running shoes would ever notice a difference physiologically even over a lifetime of regular jogging.

Only people who don't run think that. There is a major difference that shows up as the mileage increases.

Definitely worth testing. I had a difficult time recovering from a minor knee injury until I started running on grass, because the concrete was too hard on me. I would much rather run on asphalt than concrete.

quote:

Originally posted by dfez:

quote:

Originally posted by khamlerd:
I agree. I think the Mythbusters should take this one on. No doubt there is a measurable difference in elasticity between asphalt and concrete, but I really doubt that someone wearing decent running shoes would ever notice a difference physiologically even over a lifetime of regular jogging.

Only people who don't run think that. There is a major difference that shows up as the mileage increases.

Ditto. It's probably not a measurable difference for 10 steps, or even 100. But if you run 10 miles per week or more, you will notice. Lots of runners run 25-50 miles per week plus, so just think about how many times their foot hits the ground!

I think this is a valid and interesting question for runners and non-runners alike.

I'm a marathon runner and don't believe the myth. Many family members, friends and party acquaintances have told me to avoid running on concrete: to seek out asphalt roads. Very few of those giving the advice have run more than a mile at any one time. (I'm am getting a little sick of hearing them.)

Though there is a growing interest in barefoot running, I think the difference in shock absorption is relatively insignificant compared to the absorption running modern shoes provide. I would really like to see if my theory is correct and silence the arm-chair running experts.

I also feel that the human gait would have to be simulated pretty closely too. A number of elite coaches talk about running efficiency (the motion of the runners gait), which I believe can absorb much of the shock of running and decrease fatigue.

I imagine it would be no easy feat (no pun intended) to measure the difference. I agree with other post that the test would have to be conducted over a significant distance (or time,) and the impact differences per "foot fall" would be very small.

I'm not mechanical engineer, but maybe one or more load cell would be sensitive enough to record the difference.

I wonder if the major running companies do similar tests?

I agree with Matchew. I'd like to see the team test the differences between running barefoot and running with expensive running shoes. I've heard that the cushioned soles of the running shoes prevent you from sensing how hard your heel is hitting the ground beneath you, and this causes intense strain on your knees and back.

I'd really like to see this tested. I'm of the belief that the difference is so insignificant as to be inconsequential, yes, even over a long period of time at a high mileage.

I'm no ultra runner and have only run one marathon, but I've never had any injury problems and I've been running almost exclusively on concrete for 5+ years now.

I'm surprixed at all of the people who say they run but don't think there's a difference. All I can say is that you should consider yourself luckly that your knees are doing so well.

I can run one day on concrete but if I run 2 consecutive days on it, my knees will ache for a couple of days. Running on ashphalt has never been a problem. I don't use it often but my HOA put in an extremely flexible form of ashphalt around a 1/4 mile jogging track in our neighborhood. You can easily feel the give when walking on it and can even push down on it with your fingers. I believe it was developed as a softer surface for playgrounds.

This is the exact myth I was looking for.
Glad to see its already be suggested.

Documentation!
I want to see verified, reproduced documentation!
I am a 6'1", 200# recreational runner that has
run 50+ marathons and all the training that goes with them.
I can never tell the difference between asphalt and concrete.
I find it hard to believe that a sub 200# human
can exert enough force on an asphalt surface for
it to flex and absorb any significant amout of stess,
give that asphalt roads support cars, trucks, busses, etc. for
many years in all kinds of weather.

All this personal experience is nice but
it seems to come down to personal preference.
Given the wide diversity of abilities in all
the worlds runners, it may be difficult to
define an absolute answer to this for everyone.

But some kind of documented measurement of the relative
flexibility or ability to absorb shock of each
surface may still be useful.
Interesting at least.