TABLE VI. Final Ergometry Test Data

SBM DBP PP AP BR
(torr) (torr) (torr) (torr) (bpm)
: im T t T T
~ ; i
E x i 133.7 59.7 | 74.0 ; 84.3 | 92.3 |
SE jj 3.6 2.2 } 3.8 | 2d wl i
HH | i. |
i ' i
c X jj 135.5 63.000 | 72.5 {87.2 90.5 |
SE { 2.0 Ll 2.3 | 1.0 3.2
l | |
TAFV We Ve f Ve
- (cm/s) (mi/min/kg) (mi /min/kg) (rpm) ___ (ml/kg)
Tt t HN {
E x fooss | we | (267 | 18.9 15.0 |
i SE Hl 0.6 | 0.6 | 19.4 7 a7 1.6 |
4 :
co x jj 6.0 11.5 259} a7 | 15.9 |
SE | 0.5 0.7 17.0 |} 1.6 | 1.8 |
! iL 1

X = Mean SE = Standard error of the mean
SBP = Systolic blood pressure

DBP = Diastolic blood pressure

PP = Pulse pressure

HR = Heart rate

AP = Mean arterial pressure, calculated as the value of DBP + 1/3 PP

TAFV = Temporal artery blood flow velocity

%o2 = Oxygen uptake

Vg = Pulmonary ventilation

£ = Respiratory frequency

Vy = Tidal volume

bpm = Beats rer min

rpm = Respirations per min

E = Experiment in which hypoxia, orthostatic and physical fatigue tolerance
testing were preceded by four 10-min pedal ergometry periods

C = Control experiment in which hypoxia, orthostatic and physical fatigue
tolerance testing were preceded by four 10-min rest periods



EFFECTS OF PRIOR PHYSICAL EXERTION ON TOLERANCE
TO HYPOXIA, ORTHOSTATIC STRESS, AND PHYSICAL FATIGUE

Introduction.

Pilot error is a primary cause of about 74 percent of all general aviation
accidents (5), and about 38 percent of all air carrier accidents (4). Fatigue
has been recognized as one of the underlying causes of pilot error (4,6,12,13).
The Federal Aviation Administration (FAA) recognizes that fatigue has an adverse
effect on safe pilot performance. The FAA has, therefore, set limits on flight
time for air carrier flight crews.

The National Aeronautics and Space Administration (NASA)/FAA voluntary
aviation safety reporting system, which became operational in 1976, allows air
transport crews to report pezformance decrements that could be related to
fatigue (9). Since 1976, 426 reports nave been received of incidents possibly
related to fatigue. When 77 of these were analyzed in detail, 75 were deemed
to reflect substantive and potentially unsafe situations.

Difficulties in the measurement and definition of fatigue have been pointed
out (1,11,12). Some of the factors which contribute to fatigue include: heavy
physical exertion; complex, intense, and protracted psychomotor work; desynchro-
nosis with displaced or lost sleep; monotony and protracted immobility; environ-
mental factors such as temperature, humidity, noise, vibration, and barometric
conditions; poor or insufficient nutrition; age; and chronic or acute medical
conditions (9,12).

According to the NASA/FAA study (9), the factors most frequently cited
by aircrews as being responsible for fatigue were duty time, flight time,
number of flight segments, and number of duty days. Preduty activity was
cited as another factor of concern (9).

The purpose of our study was to determine the presence and degree of
adverse effects of physical exertion on pilots’ tolerance for hypoxia, ortho-
static stress, and physical fatigue and on psychomotor and mental performance.
For this study, physical exertion consisted of four 10-min periods of pedal
ergometry with 5 min of rest after each. Each ergometry period consisted of
continuously pedaling at 50 revolutions per min for 2 min at a load of 30 watts
(W), 4 min at 60 W, and 4 min at 100 W.

Methods.

Subjects. The participants were ten paid, healthy male volunteers,
20-35 years old, After a thorough briefing, each subject signed a standard
consent form. The subject then underwent medical examination, consisting of
a medical history, a standard 12-lead electrocardiogrem (ECG), a spirogram,
and a meaSurement of hemoglobin (Hb} concentration. Next, a combination
psychomotor and mentation test was taken twice by the subject for practice.
This test consisted of 20 pages of simple addition and subtraction problems
{20 per page} to be answered true or false. The subject was instructed
to meke a checkmark within the correct answer block provided for each problem.
Aliso, the checkmark was supposed to be made so that it would not touch any
of the block's boundary lines. Each answer block measured 9 mm by 20 mm. The
three scoring elements were time (min) for test completion, arithmetic errors,
and eye/hand coordinatien errors. The arithmetic score was the number of
incorrect answers per min. The eye/hand coordination score was the number of
block boundary violations per min. Previous experience showed that the


10-min ergometry periods and during the corresponding resting periods of the
control experiment. The workloads were sufficient to produce statistically signif-
icant changes in ail physiological variables, except diastolic blood pressure (DBP)
that was significantly changed only during the fourth 10-min ergometry period.

The four ergometry periods produced visible sweat in all subjects. Weight

(water) loss caused by the four periods of exertion averaged 0.37 kg, and was
significantly greater (p < 0.001) than the 0.12 kg weight loss of the
corresponding rest periods of the control expeviment.

Between the end of the fourth ergometry period, and the end of prehypoxia
control measurements, each subject rested for 30 min. Of the physiological
variables measured during the preceding ergometry, all had returned to pre-
exertion resting levels except HR, which showed a small but significant
(p = 0.028) elevation of 6.6 percent over the average control value of 62.1 bpm.

Table III summarizes the data from the five psychomotor tests taken by each
subject during hypoxic exposure. The subject's error scores obtained from
each test during hypoxic exposure after exertion were expressed as percent
of the corresponding error scores obtained after rest in the control experiment.
Although the data indicate a general trend of increased arithmetic errors,
none of tz.e increases was statistically significant.

Table IV summarizes the physiological data obtained during the iast min
of each psychomotor test taken during hypoxic exposure. The values for each
physiclogical variable during the psychomotor testing and hypoxic exposure
after ergometry were expressed as percent of the corresponding values obtained
in the control experiment. As shown in Table IV, the HbO, data indicate that
the hypoxia during psychomotor task performance was as well tolerated after
exertion as after the corresponding rest periods of the control experiment. By
similar comparison, neither HR nor pulse pressure (PP) was reduced. However,
small but statistically significant decreases did occur in one of the mean sys-—
tolic blood pressure (SBP) values, three of the mean DBF vaiues, and ail five of
the mean arterial pressure (AP) values associated with prior exertion.

Table V summarizes the physiological data obtained during LBNP testing
of orthostatic tolerance. All of the subjects easily tolerated the 2 min of
LBNP. With the exception of barely perceptible transient lightheadedness in
two subjects during the onset of LBNP, symptoms were absent. The physiological
data in Table V indicate the absence of any adverse effects related to physical
exertion. The only statistically significant difference was in SBP, which
fell less during LBNP after physical exertion than efter rest.

Table VI presents the physiological data obtained during the last 2 min
of the final pedal ergometry test. There were no adverse effects related to
the initial physical exertion.

Discussion.

These results indicate only negligible effects of four 10-min substantial
ergometry loads on altitude-equivalent hypoxia, orthostatic and physical fatigue
tolerances, and psychomotor performance at a simulated altitude of 3658 m.

Tolerance to Altitude~Equivalent Hypoxia. When a person undergoes hypobaric
altitude exposure, the ambient air partial pressure of oxygen (P0,) » the pressure
on the surface of the body, and the density of the respired air are reduced. The
breathing of an altitude-equivalent hypoxic gas mixture at ground level in this
study duplicates only the first of these three hypobaric conditions. The aviation



TABLE I. Experimental Protocol

Time (min) Activity
0 Subject arrives
Health check
15-30 Refresher psychomotor test
30-60 Body weight measurement
Instrumentation of subject
EXERCISE PHASE
60-70 Ergometry
70-75 Rest
75-85 Ergometry
85-90 Rest
90-100 Ergometry
100-105 Rest
105-115 Ergometry
END EXERCISE PHASE
115-135 Body weight measurement
Additional instrumentation of subject
135-145 Resting control measurements
145 HYPOXIA BEGINS
150-165 lst psychomotor test
165-170 Rest
170-185 2nd psychomotor test
185-190 Rest
190-205 3rd psychomotor test
265-210 Rest
210-225 4th psychomotor test
225-230 Rest
236-245 5th psychomotor test
245 HYPOXIA ENDS
245-250 Removal of ear oximeter
250-258 Pre-LBNP control measurements
258-260 LBNP (-40 torr)
265-275 Ergonmetry
275-280 Sensors removed

Rody weight measurement


learning curve for this test starts leveling off by che fourth test. Any
residual learning differences were account for in randomization of
experimental order.

The subject then entered the experiment chamber for an equipment and
protocol training session. Next, he was seated upright in ovr lower body
negative pressure (LBNP) box (8) which contained a pedal crgometer. After
adjusting seat height and pedal distance, the subject practiced one 10-min
period of pedaling with timed load segments as described earlier. For the
next 30 min he breathed an hypoxic gas mixture equivalent to that of a 3658 m
mean sea level (MSL) altitude. The gas mixture was administered through a
partial face mask which covered both the subject’s nose and mouth. For
practice, the subject took the psychomotor test two more times during hypoxic
exposure.

After completing hypoxic exposure, the subject underwent a practice
orthostatic tolerance test. This consisted of a 2-min exposure to an LBNP
of -40 torr differential pressure. After that the subject practiced a final
pedaling exercise at a 50-W load for 4 min. This completed the training
session. The subject was disqualified from further participation if, during
that session, his heart rate (HR) exceeded 150 beats per min (bpm) during
the 10 min pedaling load, his arterial oxyhemoglobin saturation (Hb0>) fell
below 80 percent during hypoxic exposure (10), or consciousness was not
maintained during LBNP exposure. The subject was also disqualified if his
monitored single-lead ECG showed evidence of ischemia or arrhythmia at any
time during the training session. The subjects' mean age was 25.5 + 1.4 years,
mean height was 69.3 + 0.7 cm, mean weight was 176.0 + 1.8 kg, and mean
Hb concentration was 15.4 + 0.2 gm percent.

Protocol and Measured Variables. Each subject participated in one
experiment per week for 2 consecutive weeks. The experimental protocoi is
outlined in Table I. Each subject ate breakfast prior to arriving at 0830.

His body temperature was measured while he filled out a heaith questionnaire.
Next, he took one timed psychomotor test as a learning refresher. He was then
taken to the experiment chamber, and three ECG electrodes were attached to his
chest. After voiding his urine, his body weight was measured. Next, the
subject was seated in the LBNP box, a blood pressure (BP) cuff was placed on
his right arm and the ECG cable was connected to monitoring and recording
equipment. He then underwent the four 10-min periods of pedal ergometry.

After completing these, the subject exited the box, voided his urine, and his
body weight was again measured. A directional Doppler sensor for measuring
temporal artery blood flow velocity (TAFV) was attached to his temple at this
time. He was reseated in the LBNP box, and loosely sealed in it. The subject's
BP cuff was repositioned, the ECG cable reconnected, and an ear oximeter
positioned for subsequent monitoring and measurement of HbO,. After 10 min

of control measurements while the subject breathed ambient air, the face mask
was positioned for the start of a 100 min exposure to the altitude-equivalent
(3658 m MSL) hypoxic gas. During this hypoxia period, five of the timed
psychomotor tests were taken consecutively by the subject. A 5 min~rest period
followed each psychomotor test. At the end of the hypoxic exposure period,

the face mask was removed, and shortly after HbO2 reequilibration, the ear
oximeter was removed. Tightening adjustment of the subject's waist seal preceded
LBNP testing of orthostatic tolerance. After 8 min of controi measurements,
the subject underwent LBNP of -40 torr for 2 min. The subject's waist seal was
then loosened for comfort during subsequent pedal ergometry, and a breathing



TABLE II. Initial Pedai Ergometry (Physiological Data)

E, Rj £E, Bp Es; Bg EE, R
T
SBP xX 164.8, 116.0 162.3, 114.7 156.94! 113.1 | 157.8} 113.8
(torr) SE 3.8 3.0 3.7 2.2 3.2 2.6 2.7 2.6
=a
i
DBP xX 62.2 60.2 62.2 57.5 60.9 58.3 62.5,| 58.2
(torr) SE 2.3 1.9 1.4 1.9 1.6 2.0 1.4 1.8
i
PP x 102.6, 55.8 100.2, 57.2 96.041 54.7 95.4.{ 55.7
(torr) sz 49°] 3.6] 3.3] 3.0) 3.3] 3.2) 3.1] 2.8
|
AF x 96.4, 78.5 95.5,! 76.5 i 92.9,) 76.6 94.2,! 76.7
(torr) SE 1.8 1.7 1.8] 1.5 1.6 1.7 1.3} 1.7
i 1 1
~ i i
i HR x i 120.5, 69.5 119.9,; 67.1 | 120.0, 66.9 | 117.5, 67.7
(bpm) SE i 3.9 3.5 4.1 2.7 ji 4. ; 3.5 3 3.5
1 I

X = Mean SE = Standard error of the mean

SBP = Systolic blood pressure
DBP = Diastolic blood pressure

PP = Pulse pressure
HR = Heart rate
AP = Mean arterial pressure, calculated as the value

of DBP + 1/3 PP
= Statistically significant (p < 0.05) displacement
of the ergometry value as compared to the corresponding
resting value of the control experiment
bpm = Beats per min
5, 2,3,4 7 Last min of first, second, third, and fourth
pedal ergometry periods
Ry 2,3,4 7 Last min of first, second, third, and fourth
resting periods of the control experiment


TU VAI LY

mt
RIGINAL
EFFECTS OF PRIOR PHYSICAL EXERTION ON TOLERANCE

TO BYPOXTA, ORTHOSTATIC STRESS, AND PHYSICAL ee IP iP i ch
‘Al ti
{ a ipa

Michael T. Lategola
Peggy J. Lyne
Macy J. Burr

FAA AM-82-4

Civil Aeromedical Institute
Federal Aviation Administration
klahoma City, Oklahoma

uarch 1982

Document is available to the public through the
National Technical Information Service
Springfield, Virginia 22161

Prepared for
U.S. DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
Office of Aviation Mediciue
Washington, D.C. 20591


TABLE IV. Physiological Data (During Psychomotor Testing and Hypoxic Exposure)

Paty Pu, Pat, Put, Pals
(% of Cont.) (% of Cont.) (% of Cont.) (%_of Cont.) (% of Cont.)
_ T
SBP X 96.2 | 96.7 97.9 97.5 95.8,
(torr) SE 2.5 1.9 1.8 1.2 Ll
DBP OX 95.2 91.0, 93.7, 92.5, 95.7
(torr) SE 2.5 2.2 2.3 1.6 2.2
PP OX 97.9 102.6 101.4 102.4 96.4
(torr) SE 5.5 4.2 3.1 3.7 1.8
\ 95.6, 93.9, 95.9, 95.1, 95.7,
(torr) SE 1.8 1.7 1.7 0.7 1.5
HR OX | 102.6 100.3 96.9 98.3 96.1
(bpm) SE 3.6 2.7 1.8 1.9 2. |
1 +
HBO, =X 100.8 101.4 101.4 101.0 102.0
(3 SE 1.3 1.3 1.0 11 1
i

X = Mean SE = Standard error of the mean

SBP = Systolic blood pressure

DBP = Diastolic blood pressure

PP Pulse pressure

HR = Heart rate

AP = Mean arterial pressure, calculated as the value of DBP + i/3 PP

HbO, = Oxyhemoglobin saturation

bpm = Beats per min

Poti ,2,3,4,5 = First, second, third, fourth, and fifth psychomotor tests

* = Statistically significant (p < 0.05) displacement of the experimental
value as compared to the corresponding value of the control experiment


GABLE Ili. Psychomotcr Test Data (During Hypoxic Exposure)

Paty Pato PaTt3 Paty, Pals
(% of Cont.) (% of Cont.) (% of Cont.) (% of Cont.) (% of Cont.)
x 176.0 136.0 109.1 122.0 88.2
A
SE 50.6 25.9 16.1 18.7 14.9
x 171.9 127.3 { 84.3 144.0 160.9
E/H
SE 43.8 26.3 20.2 36.1 29.2

1

= Mean SE = Standard error of the mean

= No. of arithmetic errors per min of total test time

/H = No. of eye/hand coordination errors per min of total test time
1T1,2,3,4 = First, second, third, fourth, and fifth psychomotor tests
% of Cont. = % of control value

bh DB pq

3

~


valve was positioned for quantitative collection of expired air. The subject
then pedaied at 30 W for 2 min and 50 W for 6 min. Expired air was quantita-
tively collected during the last 2 min of the 50-W load for measurement of
pulmonary ventilation (Vg) and oxygen uptake (VOj). After completing this
ergometry, all sensors were removed, the subject exited the box, voided his
urine and a final measurement of body weight was obtained. After completing
a questionnaire concerning symptoms during the LBNP, the subject departed.

The subject returned one week later at 0830 for the second experimental
session, To compensate for any effects of experimental order, half of the
subjects underwent the four 10-min periods of pedal ergometry in the first
experiment, ard the other half in the second experiment. In the control
experiment, the subjects remained at seated rest during the 10-min periods
otherwise occupied by pedal ergometry. The data were statistically compared
(Student's paired t test (15)) on the basis of preceding physical exertion
versus preceding rest. Statistical significance was set at a probability
value of p < 0.05.

During the four 10-min periods of pedaling, the HR and ECG were monitored,
and HR and BP were measured during the last min of each i00-W load. Specific
variables measured during hypoxic exposure consisted of: HR using a single-
lead ECG; BP using auscultative manometry; HbO (14); and TAFV (12). These
variables were also measured during the last min of each of the five psychomotor
tests conducted during hypoxic exposure. With the exception of HbO), these
variables were subsequently measured during the LBNP test of orthostatic
tolerance. These variables, as well as UE and VO,, were measured during the
last 2 min of the final ergometry test of physicat fatigue tolerance. All
gas volume data were normalized for differences in bcdy size by expressing
them as volume per kg of body weight. The CM, single-lead (2) was used to
monitor and record the ECG and HR. During hypoxic exposure, a digital
readout of HbO, was monitored for any indication of hypoxemia. The experiment
was terminated if HbO, fell below 80 percent. The pulsatile signal of TAFV
was monitored during Aypoxic exposure and subsequent LBNP testing for any
flow-reversal indication of approaching syncope (7). Criteria for immediate
termination of the experiment were: strong svbjective symptoms of impending
syncope (lightheadedness, nausea, and visual grayout, tunneling or blackout)
accompanied by hypotension and bradycardia, ECG evidence of ischemia or
arrhythmia, and TAFV approaching zero.

Simple hand signals for "everything is OK," "subjective distress is present,”
and "stop the test" were taught to each subject for communication purposes while
he was using the face mask or breathing valve. Subjects were continuously
observed; a staff physician with emergency re ‘scitation equipment was always
available on a standby basis.

Tolerance to hypoxia was assessed on the basis of adequate HbO, maintenance
and psychomotcr test performance. Orthostatic tolerance was assessed on the
basis of maintaining adequate cardiovascular function and useful consciousness
during applied LBNP. Physical fatigue tolerance was assessed on the basis of
quantitative shifts in cardiorespiratory functions during the final 50-W pedal
ergometry load.

Results.

Table II summarizes the changes in physiological variables during the


ACKNOWLEDGMENTS

The authors acknowledge the important assistance of
Mr. David Hehmayer in preparing the equipment for administering
gas mixtures.

We also thank Charles Valdez, Jimmy Lee Whitley,
Harold Dale Nelson, and Joe Nix for control and maintenance of

temperature end humidity tn the research chamber,

di


environment contains all three. Whether or not the inclusion of all three

hypobaric elements in this study would have produced different results is mut
known.

Although the psvchometor data (Table III) obtained during hypoxic exposure
indicated a trend of decreased performance due to physical exertion, none of
the effects was statistically significant. It is interesting to nete that
the greatest percent increase in the arithmetic and eye/hand coordination errors
oceurred in the first of rhe five tests after physical exertion. Thereafter,
arithmetic performance showed a general trend of improvement.

The physiclogical data (Table IV) obtained during psychomotor testing
aud hypoxic exposure reflect small but statistically significant residual
effects of the initial physical exertion. The observed decrements in SBP,
DBP, and AP in the experiments with prior physical exertion, as compared to
prior rest, might be construed as residual vasodilation, because both PF and HR
reflecting blood flow) remained generally undiminished. As reflected by
corresponding HbO, data, oxygenation was net differentially affected by prior
physical exertion. Circulatory accommodation to altitude-equivalent hypoxia
after phy vical exertion of this degree appears to be quite adequate.

Orthostatic Tolerance. Each subject underwent the LBNP test in this
study 1.3 after cessation of the fourth 10-min exercise period. The data
Table V indicate that prior physical exertion caused no subsequent adverse
effects on orthostatic tolerance. Whether or not an abbreviated exertion-recovery
tine wovld have altered the observed orthostatic tolerance is unknown.

Physical Fatigue Tolerance. The final ergometry load of 50 W for 6 min
was experienced by each subject 152 min after cessation of the preceding fourth
10-min ergometry period. As indicated dy the data in Table VI, the efficiency
of physiological functions during this final test wes not adversely affected
by prior physical exertion. The data in Tables II and VI suggest that,
immediately after fourth 10-min ergometry period, a ioad of 50 W for
only 6 min would probably have been more efficiently managed by the "openedTM
circulation than by the "less opened" circulation of extensive preceding
rest. However, in this same context, maximem aerobic capacity would probably
have Deen greater if assessed after extensive rest than after the fourth
10: ergometry period.

be
my



Technical Report Documentation Page

PTD Report No. 2. Government Accession No.

3. Recipient's Cotalog No.

|
| FAA-AM-82-4
i 4. Title and Subtitie

| Effects of Prior Physical Exertion on Tolerance to
| Hypoxia, Orthostatic Stress, and Physical Fatigue

i

5. Report Date
March 1982

6. Performing Orgenization Code

i 7 Avmsr's) yi hae? Te Lategola, Peggy J. Lyne, and

Mary J. Burr

8. Porforming Organization Repert No.

Ln

| 9. Performing Organization Nome and Address

i

| FAA Civil Aeromedical Institute
| B.0. Box 25082

Oklahoma City, Oklahoma 73125

r

10. Work Unit No. (TRAIS)

U1. Contract or Grant Ne.

12. Sponsoring Agency Neme ond Adaress

j Office of Aviation Medicine
Federal Aviation Administration

: 800 Independence Avenue, SW.

i Washington, D.C. 20591

13. TF,

ype of Report and Period Covered

OAM Report

T4-” Sponsoring Agency Code

15. Supplementary Notes

|
| Work was done under approved Task AM-A-81-PHY-122.
|

16. Abstrocr

| a period of physical exertion.

Ten healthy men, 20-35 years old, were tested for tolerance to hypoxia, orthostatic
{ stress, and physical fatigue after a period of rest and, on another occasion, after
Exertion consisted of four 10-min periods of pedal

ergometry; each period consisted of a 30-watt (W) load imposed for 2 min, 60 W for

4 min, and 100 W for 4 min.

Testing included a 100-min exposure to an oxygen/nitro- |

j gen gas mixture equivalent to 3658 m of altitude, 2 min of lower body negative

pressure (LBNP) at -49 torr differential pressure, and 6 min of 50 ® pedal ergometry.

i Psychomotor testing was conducted during hypoxic exposure.

cally significant (p < 0.05) physiological decrements were associated with prior physt
ical exertion, psychomotor performance and mentation were not significantly effected.i
In this stuéy, prior physical exertion produced nu adverse effects on physiological

i
!
|
|
j
t
| tolerances, mentatien, or psychomotor performance.
i
{
i

Although some statisti-

WT Rey Words
; Private pilots, Physical exertion,

: Cardiorespiratory functions, Psychomotor ; the National Technical Information Service,
| Springfield, Virginia 22161.

; performance, Hypoxia tolerance, Ortho-
static tolerance, Physical fatigue

j 18, Distrigution Statement

i Document is available to the public through

i
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[
i
| 19. Security Clossif. (of this report)
1

tclerance.
2. Security Clossif. (of ths page) i 21- No. of Pages if ‘22. Price
Unclassified |
{

Unclassified

|
32
!

Form DOT F 1700.7 8-72)

Reproduction of completed page authorized
i

a


NOTICE

This document is disseminated under the sponsorship of the
Department of Transportation in the interest of informatio
exchange. The United States Government assumes no liabili
for its contents or use thereof.

Ned


TABLE V. Orthostatic (LBNP) Test Data

testing were preceded by four 10-min pedal ergometry pericds

Cc = Control experimént in which hypoxia, orthostatic and physical fatigue
tolerance testing were preceded by four 10-min rest periods

SBP = Systolic biood pressure

DBP = Diastolic blood pressure

PP = Pulse pressure
HR = Heart rate
AP = Mean arterial pressure, calculated as the value of DBP + i/3 PP

TAFV = Temporal artery blood fiow velocity bpm = Beats per min
* = Statistically significant (p < 0.05) displacement of the experimental
value as compared to the corresponding value of the control experiment

SBP (torr) _ DBP (torr)
Pre-LBNP Pre-LBNP .,
Pre-Lpnp pnp tanp 90 pe-tane rane  taxp 200
j H |
x 114.1 | 108.8 95.4 , 61.9 63.3 | 102.5 i
SE 1.6 2.0 La 1.9 1.8 | 2.2 i
dH :
x 117.1 | 106.5 91.0 | 62.9 63.5 | 100.7
SE 2.9 2.9 Le 2.0 2.4 | 1.6
{
PP (torr) AP (torr)
Pre-LBNP Pre~LBNP
Pre-LBNp_upyp snp 100 pre-ipnp ianp tanp  X100
H V i ; j :
x | 52.2 | 45.5 | 87.3 i 79.3 78.5 3 99.0 :
SE | 2.0 | 2.6 3 3.4 it 1.5 1.4! 1.0 :
i i i H :
i | i :
| Xl} 56.1 | 43.0! 79.5 "i gi.0 0 ' 77.8 96.0 :
H SE |; 3.2 1 3.0 i 2.3 : 1.8 5 2.3 lel
| i i i 4
HR (bpm) TAFV (cm/s)
Pre-LBNP Pre-LBNP
Pre-LBNP_ LBNP tayp___¥100 Pre-LBNP_LBNP taxp _ *100
i | li : : ;
x 61.8 | 70.4 | 114.0 : 5.5 1 4.5 | 80.8 i
SE 3.6 j 4.3 | 2.2 0.6 } 0.6! 3.1 i
— TI i
x 62.3 72.8 155.7 ui 5.8 | 5.0! 86.7 !
SE 3.5 5.2 2.1 i 0.5 | 0.4 | 3.3 :
Ll i i
X = Mean SE = Standard errer of the mean
E = Experiment in which hypoxia, orthostatic and physical fatigue tolerance


10.

il.

13.

14.

15.

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Biackburn, H., H. L. Taylor, N. Okamoto, P. L. Mitchell, P. M. Rauteharju,
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Code of Federal Regulations. Title 14-Aeronautics and Space, Part V,

Tith
Federal Aviation Regulation Part 121, Subparts Q, R, and S, G. PL O..
Washington, D.C.

Connor, T. M., and C. W. Hamilton: Evaluation of Safety Programs With
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Connor, T. M., and C. W. Hamilton: Evaluation of Safety Programs With
Respect to the Causes of General Aviation Accidents. Volume I. Technical
Report, Federal Aviation Administration Report No. ASP 80-2, May, 1980, p. v.

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