Armored 
Medical Research Laboratory 
Port Knox, Kenjt'uc^v 
PROJECT NO, 5 - CREST FATIGUE RESEARCH 
Sub-Project No. 5-20 - Study of Schedules, Duration and 
Discipline of Rest Periods for 
Tank Crews on Long Marches 
Project No.5-20 
9 May 1944 ARMORED MEDICAL RESEARCH LABORATORY 
Fort Knox, Kentucky 
Project No. 5-20 
749o2 SPMEA 
9 May 1944 
1, PROJECT; No, 5 - Crew Fatigue Research - Sub-Project #5-2C, 
Study of Schedules, Duration and Discipline of Rest Periods for Tank Crews 
on Long Marches,, 
a. Authority - First indorsement, letter Commanding General, Head- 
quarters Armored Force, Fort Knox, 400,112/6 GNOHD dated Gent ember 24,1942, 
b. Purpose - To determine the causes of fatigue in men on long 
marches and failure to complete assigned marches. 
2. DISCUSSION 
a. In spite of the tremendous mechanization of modern warfare, 
objectives are still ultimately occupied by infantry. Even under the most 
optimal circumstances their final tasks are accomplished on foot. 
b. Frequently it is advantageous to move men rapidly on foot over 
long distances. The advantage is not real unless troops are able to fight 
efficiently after having completed the march. 
c. Many enviable records have been set of great distances which 
men have marched in a single day; yet little or no mention is ever made of 
the cost in combat efficiency of having accomplished such feats of endurance 
and litule study has been made of the ability of troops to repeat such per- 
form;* aces.day after day. 
d. These facts, together with the observed difficulties of troops 
attempting a single 25 mile road march during basic training at the ARTC, 
lead to a study of the nature of fatigue in men on long marches and the 
causes of failure to complete the assignment. 
e. Repeated marches of increasing length were studied rather than 
single record performances. 
fo For details of the experimental procedure and results, see 
Appendix* 
30 CONCLUGIQMS? 
a« Repeated daily marching over distances which are practical and 
feasible for the movement of the supplies of an army do not cause serious 
fatigue in men properly trained, fed and rested. A group of 12 men marched 
4B0 miles in five weeks and completed the last 125 miles in five days with- 
out evidence of undue fatigue. 
1 b. The causes of casualties or failure to complete an assigned 
march, are foot defects and not general fatigue. 
c, Healthy, normal young man (ages IB to 35) with normal feet, 
good footgear and proper foot care can be trained to perform long marches 
daily without casualties0 
dt Lien v.ith anatomical foot defects cannot nerforn long marches 
daily vrithout casualties* 
e. The causes of "falling out" on long marches are: 
(1) Bad feet 
(2) Improper Footgear 
(3) Inadequate foot care 
(4) Inadequate training 
($) Improper management of men as regards food, rest and 
shelter. 
f. Mechanized units which in battle will ultimately be called upo 
to march must specifically train for marching. Ability to march does not 
necessarily develop as a by-product of miscellaneous physical activity. 
g, Long marches should not be undertaken by any units without a 
thorough study of feet and footgear, together with adeouate training in 
foot care. They are no less important than the rifle. 
4. RECOMMENDATIONS: 
a. That the information in this report be made available to 
theater and training commanders0 
b, That thorough training in long marches be included in the 
training of mechanized units. 
c. That no long marches be undertaken without a thorough study of 
the foot and footgear of all personnel involved. 
Prepared by: 
William F* Ashe, Major, V.0o 
Sgt, Max Hess 
Pfc Fred Ho Glenny 
APPROVED 
.VILLA RD MACHLE 
Colonel, Pedicel Corps 
Commanding 
Incl 1 - Appendix 
Experimental Procedure and Results 
2 APPENDIX 
MARCHING FATIGUE EXPERIMENT 
lo Personnel: 
a. Nineteen (19) men employed in this study were picked at random 
from the 777th Tank Battalion, nine (9) from the Hq. Co. and ten (10) from 
the Service Co. These men had been in the Army an average of 15.2 months 
(range 6 to 3& months). All had been transferred to their present organiza- 
tion from other outfits and were very definitely not the ’’cream of the 
crop”. None had had any extensive marching since basic training. Their ages 
ranged from 18 to 39 years (avg. 23.9 years), height from 6?" to 74" (avg. , 
70o4 with shoes) and weight from 140 to 198 lbs. (avg. 160.25 lbs.). 
bs Prior to starting the experiment, each man was given a physical 
examination with special emphasis on the feet. Nine (9) men had no foot 
defects, nine (9) showed obvious anatomical foot defects and one was elimin- 
ated because of an active infectious disease0 
Co The foot defects consisted of the following: 
(1) First degree flat feet - 2 
(2) Same plus protrusion of cuboid - 1 
(3) Same plus tenderness at metarsal heads - 1 
(4) Third degree flat feet plus callous - 1 
(5) Same plus short Achilles tendon - 1 
(6) Short Achilles tendon plus callouses - 1 
(7) Second degree flat feet plus medial luxation of foot - 1 
(8) Bunion plus blisters - 1 (evidences of old blisters not 
considered a foot defects,) 
d„ During the experiment, men’slept in a standard barracks, they 
ate as desired in their regular mess, wore fatigue and winter combat clothing 
as desired and carried a twenty pound pack plus raincoat and canteen uuring 
all marcheso Water was permitted as desired tnroughout the experiment. 
2. Experimental Program; 
ac The first two weeks were spent in physical conditioning. The 
program consisted of 30 minutes calisthenics, two one-hour periods of close 
order drill, one hour on an obstacle course nd gradually increasing road 
marches of from 4 to 9 miles each day for six days a week. During this 
period, six men dropped from the experiment, three for reasons not associated 
with the tests and three because of blisters, painful feet and increasing 
anatomical defects. In all of these last three men, obvious foot defects 
were found at the time of physical examination. 
b. The actual test program began with thirteen men, nine of whom 
1 had normal feet and the other four were known to have minor foot defects* 
c0 In the first two weeks of the test program the men made daily 
road marches of the distance in miles indicated in the following table: 
TIMS 
T 
w 
TH 
F 
S 
TOTAL 
A.M., 
2 
7 
14 
7 
19 
3 
P.M. 
5 
5 
5 
67 
NIGHT 
3 
2 
5 
2 
0 
12 
TOTAL 
10 
14 
19 • 
14 
19 
3 
79 
do All road marches were made at a marching rate of 3.0 mph,walking 
50 minutes and resting ten. loon rests were one hour. On Wednesday and 
Friday , men atfcK ration at noon enroute. At all other times, they returned 
to their barracks for meals. Each, man walked an additional 10 miles daily to 
and from mess. 
e. In the second two-week period, the same schedule was followed 
except that the mtn were allowed to determine their own pace and length of 
rest periods* 
f0 During this four week period, half of the marching was cone on 
finished roads and half cross country. The work was done in January. Approx- 
imately half the time, the weather was clear and cold (20° - UQU F.)e The 
other half, there was either rain or snow daily* 
g0 During the fifth and final week of the experiment, the men 
marched 25 miles daily for five consecutive days at their ovm pace determining 
their own rest periods No effort was made to keep the group together and 
stragglers came in as they chose* Again half the route was on finished roads 
and half cross-country. The ground was very wet and muddy throughout the 
week. 
3o Data: 
a* Daily determination of stripped weights were made throughout 
the experiment. 
b0 The rectal temperature and standing pulse rate were measured 
before and after each march* The actual weight loss during the march was 
measured and urine specimens before and after work were examined for evidences 
of albumen, sugar and ketone bodies., 
Co Ken with any complaints were examined by a medical officer daily 
and all men were seen twice daily in the final week (125 miles in 5 days). 
2 L o. Results: 
a, During the first two weeks of the test program, one additional 
man was dropped because of his refusal to carry out instructions and because 
of his deleterious effect upon the morale of the group. The remaining 12 
completed part or all of the five week test program during which they marched 
480 miles. In the last five days, they marched 125 miles and all, by their 
own request, went to a U.S.O, dance on the evening before the last day. All 
finished the final hike without difficulty in an elapsed time of 7 hours and 
45 minutes. In the last week, the group showed an average weight gain of two 
pounds each, and no man lost weight during this period. 
b. Marching rate and rest periods. 
(1) Early in the experiment, the men expressed the feeling that 
marching rates of 2,5 raph and 3 mph were a little too slow for comfort on 
finished roads. Also they complained rather bitterly about being forced to 
take a ten minute rest period each hour. Because the weather was cold and 
often wet, the men felt that the rest period made them stiff and uncomfortable 
thereby doing more harm than good0 
(2) In the second two-week period, the men selected their own 
marching rate and determined their own rest periods. Over this two-week 
period and the final week, the marching rate as determined by total distance 
and elapsed time varied between 2,B and 3*2 miles per hour, depending on the 
terrain and rnud. Rest periods ..ere limited to five minutes in the morning 
and were not changed in the afternoon if the weather was cold; but were fre- 
quently 10 minutes if adequate shelter could be found. Occasionally men 
preferred to march two full hours without a break followed by a 15 minute 
rest under shelter before proceeding. Most men felt that a break at the end 
of the first hour in the morning was wholly unnecessary except to adjust 
socks and have a drink. 
c. Casualties occurred from time to time during the first four week 
period. In all but one case the cause was foot trouble. This man developed 
severe irritation between his thighs and buttocks. He was off duty two days 
and then continued throughout the experiment ..ithout difficulty. Three men 
were unable to wear leggings because they rubbed the calf or shin-bone raw. 
No time was lost. In no case, did any man drop out because of general physi- 
cal exhaustion. Those who dropped out or fell behind did so solely because of 
painful feet (or legs improperly used because of a foot lesion). 
(l) No man who had normal feet to start with had to drop out 
because of foot trouble, jrour of these did develop blisters which were 
treated successfully ’without interference to their activities. In all cases, 
slightly larger shoes and the use of cushion-sole socks prevented any further 
trouble. 
(2) All of the men with anatomical foot trouble had sore,tender 
3 and bruised feet roughly in proportion to the extent of the 
original lesion. The men with short Achilles tendons had 
great trouble early, but.were all right by the end of the 
period, The men with flat feet lost, on the average, 25% 
of the work time. Ail were offered the chance to drop out 
entirely and refused. By judicious care and foot exercises, 
all were doing at least 3/4 of the program at the end of a 
month and two were much better than before they started,, 
Almost all of these men had poorly fitting shoes, wore inade- 
quate socks and knew nothing about foot care. 
d* The temperature and pulse data added nothing of practical value,. 
The urine showed increasing amounts of albumen and ketone bodies as the 
length of the march increased. These evidences of fatigue for any given 
march were definitely less or even absent in the fourth week as compared with 
the first week - evidence of improved physical condition or increased work 
efficiency. In no instance was the condition of significant severity and it 
always cleared up entirely before the next day’s workc Weight losses per 
mile marched were slightly greater in the men with bad feet. The group 
average weight loss seemed to be more a function of the average ambient 
temperature than of the length of the march. It was never as much as 5% of 
the body weight0 The group lost weight curing the training period and the 
first two weeks of the experimental period* Thereafter, there was a steady 
weight gai 
e0 In the final weak, the men marched 25 miles daily for five conse- 
cutive days, each day over a different course. Marching rates based on total 
elapsed time were as follows; 
(1) 20?B mph 
(2) 3ol mph 
(3) 3cl mph 
(4) 2o9 mph 
(5) 3c2 iaph 
Rest periods during the hike were as follows; 
(1) End of 1 hour - 3 min. 
(2) End of 2 hours - 5 min0 
(3) End of hours - 40 min, lunch 
(4) End of 5| hours - 10 min, 
(5) 2nd of 6)J hours - B-12 rain0 
Eight men finished all of the hikes without difficulty. Two men finished 
four of the hikes and completed 20 miles of the other one. One nan completed 
three; did 20 miles, and 10 miles on the other two0 One man completed two 
hikes; did 10 miles, IB miles and 20 miles respectively on the other three* 
All men finished the first and fifth hikes. All uncompleted hikes were due 
4 to sore feet and blisters rather than to fatigue. Those who did not 
complete all hikes were men with apparent anatomical foot defects. There 
was an average weight gain during this week of 2 lbs0 each, and no man lost 
weighto Albumen and acetone in the urine were less on the fifth day than 
on the first. All twelve went to a dance on the evening of the 4th day and 
all twelve finished the hike of the 5th day in a group0 
5o Summary: 
a0 The purpose of the experiment was to find out how far trained 
men can march; and, when fatigue stops them, what are the manifestations of 
that fatigueo 
b. Serious fatigue never appeared and the only limiting factors 
were the condition of the feet and footgear. 
c. All of these men could have fought for their lives at the end 
of 125 miles marching in five days* 
d0 Men without foot defects thoroughly trained for marching, given 
proper and adequate food and rest, can move forward without undue fatigue 
at rates and over distances greatly in excess of those commonly accepted,, 
e0 The experiment was stopped not because the men had done too 
much, but because it seemed impractical to go farther. All were willing and 
able to attempt 35 miles per day (1C.5 hours). 
f0 The ability to perform repeated long marches requires training 
for that task and it is fallacious for mechanized units or any others to 
assume that marching ability will necessarily come as a natural by-product 
of miscellaneous hard physical activity,, 
go No unit, mechanized or otherwise, should be required to take 
long marches unless there has been a thorough study of feet and footgear, 
together with detailed training in foot care. The feet are no less 
important than the rifle to the infantryman0 
APPENDIX 
5