Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-03-22
Survey by U. S. Public Health
Service Cites Exact
Statistics.
MAXIMUM GROWTH
RATE REACHED AT II
Systematic Physical Exercise In.
creases Height. Weight and
Vital Capacity.
BY THOMAS r.. HENRY.
4 man is strongest at 30.


Once he has passed his thirtieth
birthday he starts slowly but steadily
down hill toward old age
He reaches his maximum rate of
growth at II, but continues to grow, in
some respects, until he is so.
Systematic physical exercise in
creases height, weight and vital Ca
pacity.
These facts are shown by survey
Just completed by the United States
Public Health Service in which exact
measurements were made of several
thousand men and boys in an effort to
settle the much disputed question of the
relation between age and strength and
growth. Statistics were obtained for
ages between and so.
Growth Checked Abruptly.
Height, the figures show, rises steadily
and rapidly from 3 to II. when growth
stops rather abruptly The child at
Is slightly more than half as tall
as he will be at the maximum. He
weighs only about one-fifth as much
as lie will when he is 90. Weight con-
tinues to increase rapidly between II
and 20, when the maximum rate of
growth Is reached. but there Is slight
continuous increase through adult life
Chest measurement rises rapidly until
II, after which the rate of growth is
very Sow but the maximum is not
reached until late in life.
The vital capacity, or air capacity
of the lungs, increases from to II
in about the same way as height. After
that 1t begins to decline and continues
through life. Lung air capacity starts
at 3. with only about 20 per cent Of
the maximum at II, while the 3-year-
as great as that of the young adult
The greatest increase in vitay capacity
comes between IA and II.
Pressure Rises Rapidly in Young.
Systolic and pulse pressures rise very
rapidly among children, the pulse pres
sure reaching its highest point at l8
or 1e. Pulse pressure gradually falls
during adult life. Systolic pressure rises,
but very gradually. The diastolic blood
pressure increase is most rapid among
children.
The relation of physical exercise to
growth was shown to be positive in
measurements of approximately 1000
New York City school boys. One growth
was given regular physical training
for a few months and checked against
control group.
Growing boys may be expected to
show increases in height in the course
OF a few months" says the report
Thus the group not given the special
exercises and requested to take as little
exercise as possible, gained on the aver
age about two-thirds of an inch. But
the experimental group gained nearly
an inch during the four months
In weight, the boys given the ex-
ercises showed an average gain of 3.3
pounds, while the control group showed
a gain Of two pounds.
The study was carried on primarily
to ascertain whether gymnasium work
would have definite effect on the
posture of boys. An improvement in
muscular tone seems unquestionable,
since a series of strength tests taken
before and after the experiments in
dictated that the boys In the special
classes increased more rapidly than
other boys of the same ages. All meas
urements of posture, however, indicate
no difference"
Flst-footedness. the survey showed
apparently was not improved by exer-
else. The results with blood pressure
and pulse rate were unsatisfactory.
The study of the relation between
general physical fitness and strength
was carried on with 1900 individuals
in New York City between and IS
years of age Figures were obtained
for the strength of the hand grip. push,
pull and lifting muscles, lung force and
lung fatigue.
Pulling Harder Than Pushing.
Pull, it was found, starts at about
so pounds for 15-year-old boys, rises to
a maximum at IS to 20 years, then
falls slightly. Push starts at about 10
pounds and also reaches a maximum at
about 20 years of age. Pushing strength
appears considerably above that of
pulling.
Lung force begins at IA at about
102 millimeters, rises to about 1856 as
adult life is reached, and after that
continues to 60 up very slowly. Lung
fatigue, measured in seconds, shows
practically no relation to age between
Is and so.
Outside of lung fatigue, or ability
to hold ones breath" says the report,
I'VE find that all the strength tests
rise during adolescence in much the
same manner, squirt upward at puberty,
reach a maximum at about 80 years
and then decline slightly. All the tests
show great variability from person to
person at any one age, especially lung
force and lung fatigue"
The study was conducted by Sur
geons Louis Schwartz and Lewis r..
Thompson and Associate Statistician
Rollo II. Britten.
----------..--- s---------~----