Evening star., 1925-09-13
SCIENCE MEASURES
ATHLETES ABILITY
Can Tell by Physiological
Study What Branch of Sport
a Man Is Fitted For.
BY Science Service.

BY Science Service.
SOUTHAMPTON. England.-What
kind of sport a student is most likely
to excel in may be determined by a
physiological examination, according
to Prof. A. V. Hill of London Univer-
sity. In giving the presidential ad-
dress before the physiological section
of the British Association for the Ad.
vancement of Science. in session here,
he showed curves. based on many
years of experimentation, from which
II is possible to tell how many yards
a man can run without exhaustion
and what is his best speed. He finds
that this depends chiefly upon the
ability to supply sufficient oxygen
from the air and TO dispose of the
products of combustion accommodating
in the muscles from exertion. The
oxygen used by the body Is the meas
ure of the energy expended. One liter
of oxygen, about one quart, would be
sufficient, if it could be used with a
hundred per cent efficiency, to raise
a weight of l ton TO height of Z
feet
May Borrow Oxygen.
In running, the oxygen needed In
creases as the square or cube OF the
speed. That Is, running twice as fast
oxygen per minute. A man taking
240 steps per minute may consume
S lters of oxygen minute, while II
he speeds up to $50 steps he may
require ~ liters. But a runner may
for short time consume more oXy-
gen than he can breathe in. just as
q man for a while may spend more
than his income. An athlete. for in
stance, may have maximum intake
of literS a minute and be capable
of running into debt for oxygen to
the extent of 10 liters. If then he
was running at a speed requiring 5
liters of oxygen a minute. he would
have to draw on his reserves at the
rate of a liter minute, and at the
end Of 15 minutes would be exhausted. d.
This possibility of thus overdraw-
ing ones oxygen income depends upon
a mecha anism of the muscle by which
tactic acid, the sour milk acid, may
be accumulated to be oXidiZed off when
the exercise is over. The muscles,
therefore, serve as storage batteries
for energy to be drawn upon in an
emergency and recharged when the
man has leisure to catch his breath
again. The inability of women to
match the highest athletic records of
the men is due to their lesser energy
reserve. Women may have as much
skill as men, but on the average they
can eXpend in a given time 81 per
cent of the energy available to men.
DR. Hill suggests:
AN enterprising woman athlete who
wants TO break a record should avoid
the 800 meters: she would be well
advised to try the 500 meters"
Mechanics of Jumping.
The scientific study of the feats of
trained athletes discloses facts that
would have appeared incredible. For
instance, DR.. Hill says of the me-
chanics of high jumping:
"Paradoxical as it may seem, II is
possible for an object 10 pass over
a bar while its center of gravity
passes beneath; every particle in the
object may go over the bar and yet
the whole time it's center of gravity
may be below. A rope running over
a pulley and falling on the other side
Is an obvious example. 1t is con-
ceivable that by suitable contortions
the more accomplished high jumjers
may clear the bar without getting
their centers of gravity above or ap-
preciably above 1t. Let us calculate
however. on the assumption that the
center of gravity Of a jumper just
clears the bar. The world record
nigh jump Is b.6l feet, the center of
gravity of the performer being pre-
sumably about 3 feet high at rest.
He raises it, therefore, 3.61 feet into
the air, from which we may calculate
that the whole time occupied in the
jump is about 0.96 second Seeing
the amazing compleXity of and the
skill involved in the rapid movements
and adjustments involved in a record
high jump, it is striking that all those
events can occur within a time of
less than l second"