I don't buy it. Fall down on concrete and fall down on asphalt and tell me which on
hurts the most.
You're wearing shoes that absorb shock and you have insoles that do the same. Drop the
golf ball on a
piece of foam that is on a layer of air(gel, water, whatever) and see how high the
ball bounces.
In Boulder you'd take your life into your hands running on some of the sidewalks
because they were so
uneven, broken, and torn up. In other places the crown of the road was so high it
would throw your back
out if you ran on it for very long. In other places the traffic was so crazy it was
life threatening.So,
you take the lesser of the evils and go for it.
JL
Mike Prizy wrote:
I just did the golf ball drop test and used my mail carrier - who just delivered my
September 2002
TFN - as the judge. He said it was difficult to tell, but that the ball seemed to
bounce higher from
the sidewalk, though I think the rough asphalt surface made the golf ball take an
angular path,
appearing to bounce not quite as high.
However, that is with two hard objects. I think the difference in variables with a
runner - shoe
density, shoe wear, form, mechanics, speed, etc. - will make the differences
insignificant.
Grass will make you last.
Kurt Bray wrote:
Mike says:
The only asphalt I ever saw that was significantly softer than concrete was
on
country roads when I
ran in college. The only other asphalt I ever saw that was softer than set
concrete was the asphalt
just before the steamroller went over it.
Here's a simple experiment you can try. I did it myself a few minutes ago
to confirm what I'd heard. Find a flat area that has both asphalt and
concrete - say a parking lot with a sidewalk next to it. Stand on the
concrete and drop a golf ball held out at shoulder height. It will rebound
about up to your waist. Now step over and do the same on the asphalt, and
you will see that bounces only up to about a little over your knees.
Conclusion: there IS a noticeable and measurable difference in the hardness
of the two surfaces.
Add this difference up over and over again though hundreds of thousands of
footfalls, and it could make a real difference in injury risk.
I certainly agree with those who say that dirt is even better (the ball
hardly bounces at all on dirt), and I do the majority of my own running on
dirt for that very reason. But if you are running in an urban setting and
you have only the choice between asphalt and concrete, take the asphalt.
Kurt Bray
_
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