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Jesus Dapena
09-09-1996, 06:14 AM
Dear Biomch-L-ers:

Some time ago, Herk Confer asked if the running track for the
Atlanta games was a "tuned" track. I have some answers now. Phil Henson,
who was "Competition Manager / Athletics" (essentially, the Meet Director
for track & field) at the Atlanta Olympic Games, and happens to be a faculty
member at my Department just gave me the necessary information.

As expected, the track was not "tuned". Track "tuning" generally
refers to the design of the STRUCTURE underlying the track. While an indoor
track may have some structure below it for support, an outdoor track does
not. For outdoor tracks, asphalt is poured directly on the ground, and
flattened with a steamroller (essentially like the process used for a normal
road), and then a rubber-like surface (Tartan, Rekortan, Mondo, etc.) is
poured on top of the asphalt, possibly in more than one layer. This is how
the Atlanta track was built, without any "tuning" structure below it.

It is generally believed that harder track & field tracks produce
faster times in the sprint events, but harder tracks may also lead to
injury, particularly if athletes train on them day after day. They may also
be uncomfortable for distance runners. Therefore, the International Amateur
Athletic Federation (IAAF) has set a limit for the hardness of tracks.

The test is the following: A 20 kg mass is allowed to fall onto an
anvil which transmits the load via a spring (1750 - 2250 kN/m) to a test
"foot" (a 70 mm diameter spherical base of 500 mm radius) which lies on the
surface to be tested. There is a force transducer between the spring and
the foot. The 20 kg mass is dropped from a height of 55 mm. The "force
reduction" measure is calculated as follows: Force Reduction (%) =
[1-(FS/FC)] x 100, where FS is the peak force recorded on the surface being
tested, and FC is the peak force recorded in concrete. (For more details,
see Track and Field Facilities Manual, IAAF, 1995 --ISBN 3-921896-81-9--,
pp. 90-92.) The rules say that the Force Reduction "shall be between 35%
and 50%".


Phil tells me that the Atlanta track tested at 36% Force Reduction,
so it was very hard, and barely squeezed through the IAAF limits. The track
was not designed for training, since it is to be turned into a baseball
field -- maybe it is being torn down right now! The hardness of the track
may have contributed to the excellent results in the sprint events ... and
also to some complaints of discomfort by distance runners: You can't please
everybody!

Jesus Dapena
---
Jesus Dapena
Department of Kinesiology
Indiana University

Bloomington, IN 47405, USA
1-812-855-8407
dapena@valeri.hper.indiana.edu
http://ezinfo.ucs.indiana.edu/~dapena

The Atlanta track was very hard