were expended within 30 minutes of actual
work, It appears evident that the physical
working capacity of regularly active people
does not follow the age related trend of deter-
ioration as seen in the “normals.” In subjects
up to 57 years of age, a sufficient period of
physical training elevated the working capacity
considerably above the slumping line of aver-
ages. It should be mentioned that a peak oxy-
gen intake of 35-40 ml/kg/min, equivalent to
an energy expenditure of 10-11 times the basal
metabolic rate, represents an “average” level
of physical fitness while values above 40 ml/kg
indicate superior, values below 35 ml/kg in-
ferior levels of work capacity.

The individual approach of studying age-
related physiological changes over the years
was used by Dill’ with himself as an experi-
mental subject. This exceedingly active inves-
tigator of environmental and exercise stresses
has never really attempted to attain or to main-
tain maximum levels of functional capacity.
Experimental data of his peak oxygen intake
and maximum heart rate over a period of 35
years, from age 36 to 71 are shown on Fig, 3.
The dashed line, indicating his performance
drop-off over the years, approximates closely
the average curve established by Robinson,

The solid line, in contrast, represents per-
formance data of a subject who made special
efforts to regain the highest possible level of
work capacity after unavoidable fitness slumps
due to detrimental living conditions, accidents
or diseases, Evidently, sufficiently long pe-
tiods of inactivity caused a reduction of physi-
cal working capacity toward the average level
observed in the “normal” population. The re-
turn to peak levels of performance capacity
was depending on the type, the intensity and
on the frequency of regular physical exercise.

An age-related decrease of maximum heart
rate during physical efforts has been reported
by several authors."" The results on Dill un-
derscore these observations convincingly, But
here again, for the individual staying physio-
logically younger through physical training,
there might be exceptions to the general rule.
In Balke’s case, the relatively low values ob-
served after passing the age 50 appeared to
have been caused by extreme training efforts.
This was concluded from experimental results
of two young cross-country runners who after
hard training, did not exceed 168, respectively
172 beats per minute during maximum effort.
The fact that such reduction in maximum pulse
frequency must not be considered an indication

MAXIMUM HEART RATE AND OXYGEN INTAKE VERSUS AGE

w
& 190
z
. ft
<= 170
Zz]
cd
3 1S0r Cross country runners
! .

, oop /
g +f i y ow:
z "4 / ~_
ZEs0b mayb, :
Ze Low ae v7 ;
ge \,

S4oh Min
83 Wasa
=
ind 30r

Ca, 1962

AGE IN YEARS

Ficure 3. Maximum Heart Rate and Oxygen Intake Versus Age.

~3-


REFERENCES

. Norris, A. H. and Shock, N. W.: Exercise
in the adult years, Chapter in “Science
and Medicine of Exercise and Sports.” Edi-
tor Warren R, Johnson. Harper and Bro-
thers Publishers, New York; 1960.

. Jokl, Ernst: Alter und Leistung, Springer-
Verlag, Berlin, 1954,

. Diem, Carl: Sport und Alter. Lecture at
18th German Sportsmedical Congress,
Hamburg, 1957.

Mateeff, D.: Morphological and physio-
logical factors of aging and longevity.
Chapter in “Health and Fitness of the
Modern World.” Published by The Ath-
letic Institute, Illinois, 1961.

. Dawson, Percy M.: The influence of aging
on power and endurance in man. Research
Quarterly, 1945.

10.

ll.

-~6-

Robinson, S.: Experimental studies of phy-
sical fitness in relation to age, Arbeits-
physiologie 10:251, 1938.

Hollmann, W. and Knipping, H. S.: Die
Bestimmung der menschlichen Leistungs-
faehigkeit, Chapter in “Health and Fit-
ness in the Modern World.” Published by
The Athletic Institute, [linois, 1961.

Balke, B. and Ware, R. W.: An experi-
mental study of “physical fitness” of Air
Force personnel. U.S, Armed Forces Med.
J. 10:675, 1959.

Dill, D, B.: Fatigue: a case history, J. Am.
Ger, Soc. 9:1025, 1961.

°
Astrand, I.: The physical work capacity of
workers, 50-64 years old. Acta. Physiol.
§cand, 42:73, 1958,

Astrand, P. O.: Experimental studies of
working capacity in relation to sex and
age. E. Munksgaard, Copenhagen, 1952.

4 US GOVERNMENT PRINTING OFFICE : 1964 0 - 719-715


WORK CAPACITY AND AGE
(ROBINSON, 1938)

a
°°

o
°

a
°

MAXIMUM OXYGEN INTAKE
(ml/kg Zemin)

AGE

Ficune 1. Wotk Capacity and Age (Robinson, 1938).

and reported in 1938, The first illustration
(Fig. 1) summarizes his findings on 95 male
subjects. Utilizing the maximum attainable
oxygen intake per unit of body mass as the
physiologically most meaningful index of physi-
cal fitness, he demonstrated that work capacity
had its peak at age twenty, then declined to
79 per cent of this peak at age forty, to 67
per cent at age sixty, and became reduced to
less than 50 per cent toward the age of eighty.
A similar trend of age-depending loss of work
capacity was reported by Hollmann and Knip-
ping in 1960," '

- 1

“The experimental results of more recent in-
vestigations’ on large groups of the male popu-
lation in the U.S.A. deviate considerably from
Robinson’s data. (See Fig. 2), Apparently,
the average fitness level now is much lower
than it was in 1938, An attempt was made to
separate “normal individuals” (represented by
solid dots) from those who had been in pro-
grams of regular physical exercise for at least
twelve weeks (open circles), Only such indi-
viduals were considered “regularly physical ac-
tive” who had three or more weekly exercise
periods in which at least 350-500 kcal of energy

‘

4 WORK CAPACITY AND AGE

55

50

Normale, NeZ3e
J Reguleringotiv,
te Ne:

45

40

35

30

25

MAXIMUM @KYGEN INTAKE (mi/kg/min)

20

30

40
AGE

50 60 70 80

Ficune 2. Work Capacity and Age.
; -2-


MAXIMUM CARDIAC OUTPUT VERSUS AGE

suoucer | yeas | “ign | Mmit| Sica | Hee
Ph. | 23 79 | 379 | 32.0] 172
Pa | 26 BI | 344 | 33.2] 180
Fi. | 27 7a | 403 | 31.1 | 168
Na | 28 79 | 3.48 | 34.0 | 180 1
Bo. | 53 76 | 3.63 | 336 | 172 ‘

J
Subjects run regulorly 3-6km three times a week.

Taste 1.

of faltering cardiac capacity is illustrated in
Table 1: of five regularly active subjects, four
being in their twenties and one above fifty, all
having nearly the same body weight and su-
perior functional adaptive capacities, similar
cardiac outputs were found during maximum
physical efforts despite slight differences in
maximum heart rates,

Another evidence for the potential value of
regular physical exercise in reversing the proc-

ess of physiological aging is presented in the
following: a man, age 53, slightly overweight,
holding a job which frequently involves great
mental and psychological strain and tension
(air traffic control), contacted us for advice
concerning a steadily increasing blood pres-
sure. Despite medical treatment the hyperten-
sion had progressed during the last 3 years (see
Fig. 4), Presently, in a state of complete re-
laxation, the readings were 184 over 111 mm Hg.

Ch. P., Agee 53
START , ON TRAVEL
zr TRAINING i STATUS
g 200
mm o—_—,
180 = om .
5 80 , wea cab ace SYSTOLIC BP
& 140 etme
£ 120
& us }
2 100 wo ne , Masaaki yp sible ma ann nn! WU GRASTOLIC BP
/
g 80 ¥ . .
2 80
g - ;
rane ee
? 2 °° ‘ss PULSE RATE
@ sob,
pot Pe ee a
1960 61 62 63 (2346867 B69 OT
YEAR WEEKS OF
: . REGULAR CONDITIONING EXERCISES
.
Ficure 4,

Blood pressure and heart rate before and during a program of regular physical

exercise.

~4-


AD 431 301

EXPERIMENTAL EVALUATION OF
WORK CAPACITY AS RELATED TO
CHRONOLOGICAL AND
PHYSIOLOGICAL AGING

TEPRODUCED BY
NATIONAL TECHNICAL
INFORMATION SERVICE

, US. DEPARTMENT OF COMMERCE
SPRINGFIELD, VA. 22161

FEDERAL AVIATION AGENCY
AVIATION MEDICAL SERVICE
AEROMEDICAL RESEARCH DIVISION
CIVIL AEROMEDICAL RESEARCH INSTITUTE
OKLAHOMA CITY, OKLAHOMA

SEPTEMBER 1963



After several control tests had been performed,
this individual was subjected to a regular pro-
gram of physical exercises because it had been
observed on several occasions that slightly hy-
pertensive people had become temporarily nor-
motensive after good physical work-outs, The
training was begun with carefully monitored
interval work on the bicycle ergometer and
treadmill and progressed to ball games, rope
jumping and out-door running. The plot of
his average daily resting blood pressures and
pulse rates for each week following the begin-
ning of training indicates an activation of phy-
siological mechanisms normalizing the cardio-
vascular tonus, Even under great psychological
pressure, as during the 6th week of training
filled with examinations, and during the 10th-
12th week of a heavy schedule as an instructor
in class work, the pre-exercise resting blood
Pressure never came near the originally ob-
served values, Post-exercise blood pressures,
measured approximately 15 minutes after ces-
sation of the daily exercise, were usually 10-20
mm Hg lower than the pre-exercise values,

The twelve weeks of regular training did not
only result in a considerable normalization of
blood pressure but also in a remarkable 25 per
cent increase of work capacity, as Fig. 5 dem-
onstrates. Before training, definite cardio-
respiratory limitations occurred, in our stand-
ardized fitness test on the treadmill, at an
energy demand of close to 10 times the basal
metabolic rate but after training at demands
of 12.5 Mets, The lower pulse pressure and
pulse rates, not only during rest but also at any
comparable work load, were indicative of
greater economy and less strain on part of the
systems involved in the blood transport, Phy-
siologically, these results had to be considered
a rejuvenescence of essential organic functions,

Summarizing, then, it can be said that physi-
cal activity of adequate quality and quantity
modifies the pace and the intensity of physio-
logical aging. Experimental observations on
many more people who will volunteer to strive
for optimum fitness throughout their life time
are desperately needed.

ESSENTIAL HYPERTENSION (BENIGN)

Ch.P., Age #53

ry
°

€ -—: BEFORE
5 on - AFTER
: - a
. 160 a oo 12 weeks of reguiar
re) Pal oa \ conditioning exercises
& 130 — ” NN {4-5 times a week)
=
w 100 PULSE RATE a
a my
3 .
3
a 70
230
z
E 200 SYSTOLIC
€
Yor B
$
ra
@ 140 :
=
a 110 SEE DIASTOLIC HS nnn
8 = eS 15
3B 80 v 10 2
u
S =
. coo,
R 5 10 15 20135
TREADMILL TEST — TIME IN MINUTES — RECOVERY
Ficure 5. Cardiovascular response to gradually increasing work before and after physical

conditioning.

-5-


EXPERIMENTAL EVALUATION OF WORK CAPACITY AS
RELATED TO CHRONOLOGICAL AND PHYSIOLOGICAL AGING ?

A. on
BRUNO BALKE, M.D.
Chief, Biodynamics Branch

‘ 63-18

FEDERAL AVIATION AGENCY
AVIATION MEDICAL SERVICE.
AEROMEDICAL RESEARCH DIVISION
CIVIL AEROMEDICAL RESEARCH INSTITUTE
OKLAHOMA CITY, OKLAHOMA
SEPTEMBER, 1963 -

~


EXPERIMENTAL EVALUATION OF WORK CAPACITY AS
RELATED TO CHRONOLOGICAL AND PHYSIOLOGICAL AGING

BRUNO BALKE, M. D.

STRACT

2= consequence of aging. The question has been
3 le result Fe
exceptions from the

cathe oil reason
2 capacity is only deve and maintained throu;
“acceptable”
‘demands. Within this concept,

_piagiclsical
\divic

rameters, indicative for
over the years whereby

+‘ =the functional adapt

'& sociated with aging
- results encoura;
's for the mitigation of such

,
i

INTRODYCTION

Common knowledge {points to the fact that .
advancing age is associated with a decrease of
man’s capacity for strenuous physigal efforts.
Experimental studies,, confirming such general
observation, were critically reviewéd by Norris
and Shock in 1960.'_ These authors, however,
mentioned the need for more physiological ex-
perimentation on older people who had pre-
served high performance capacity levels through
regular physical training. Jokl,* in 1954, evalu-
ated perfdtmance data of more than a thousand
50 to 80 year old men competing in gymnastics
and track events, and concluded that continu-
. ous physical training appeared to be the most

efficient antidote against physiological aging.
Carl Diem,’ in a fine lecture on “Sport and

“S- consequence of training, environment, inactivity,
at age 56 nearly to that observed at age

«situation, an individual (age 53) with essential hypertension, a ¢ a disease confi
of the vascular tissue, has been
ging the Appliation of an individually devised program of rephlar activities

om Research statistics has established the fact that ph physical we work capacity declines as a

however, if this decline is the

senescence or merely due to changes in living habits. Great numbers
= ot pene have been comply with the..
Fe le on the basis of

might be a more adequate balance of essential factors in daily life such as
n- work, rest, tension, "epee a physical activity, and © others.

Statistics. is. inclined to explain
biol ogical characteristics but
‘As maximum performance

hard training, the vation of an

preservi
level of work capacity requires frequent exposures to ‘Satficiently high functional
two situations under exper

rimental scrutiny are of interest:

Rhee “Performance ity,{ were intra-
s of work apparent as
disease and retraining: latter restored

In the second
to be as-

studied over\ months with

Age,” in 1957, cited numerous examples of el-
derly individuals with extremely well preserved
performance capabilities, Mateeff* pointed out
the importance of physical exercise upon ce-
rebral activity and emphasized the correct com-
bination oF mental and physical activities for
preserving a high functioning capacity of the
brain cells.

There are two ways of conducting an inquiry
into the effects of age, namely, the statistical
study of different age groups, and the study of
individuals as they progress from decade to
decade. This was pointed out in 1945 by Daw-
son’ who adopted the second way and now, at
age 90, has accumulated a large set of perform-
ance data on himself.

A classical group study on “physical fitness in
relation to age” was done by Sid Robinson,"

-1-