Washington: People may someday be able
to run at 40 miles per hour, say researchers.
A new study, published in the `Journal of Applied
Physiology`, has offered intriguing insights into the biology
and perhaps even the future of human running speed.
Lead researcher Peter Weyand of Southern Methodist
University said: "The prevailing view that speed is limited by
the force with which the limbs can strike the running surface
is an eminently reasonable one,"
"If one considers that elite sprinters can apply peak
forces of 800 to 1,000 pounds with a single limb during each
sprinting step, it`s easy to believe that runners are probably
operating at or near the force limits of the muscles, limbs.
"However, our new data clearly show that this
is not the case. Despite how large the running forces can be,
we found that the limbs are capable of applying much greater
ground forces than those present during top-speed forward
In contrast to a force limit, what the researchers
found was that the critical biological limit is imposed by
time -- specifically, the very brief periods of time available
to apply force to the ground while sprinting.
In their study, the researchers took advantage of
several experimental tools to arrive at the new conclusions.
They used a high-speed treadmill capable of attaining
speeds greater than 40 miles per hour and of acquiring precise
measurements of the forces applied to the surface with each
footfall. They also had subjects` perform at high speeds in
The researchers found that the ground forces applied
while hopping on one leg at top speed exceeded those applied
during top-speed forward running by 30 percent or more, and
that the forces generated by the active muscles within the
limb were roughly 1.5 to 2 times greater in the one-legged
hopping gait by the subjects.
"Our simple projections indicate that muscle
contractile speeds that would allow for maximal or near-
maximal forces would permit running speeds of 35 to 40 miles
per hour and conceivably faster," co-researcher Matthew Bundle
of University of Wyoming said.