Evaluation of a standardized physical training program for

Journ.t o£S~~and Conditioning Research, 2005, 19(2), 2'46-253
C 2O05NationalS~gth& Conditioning Association
JOSEPH KNAPIK,1 SALIMA DARAKJY,l SHAWN J. SCOTT,2 KEITH G. HAURET,I SARA CANADA,1
RoBERTO MARIN,1 WILLIAM RIEGER,2 AND BRUCE H. JONES1
'US. Army Center fi>r Health Promotion and Preventive Medicine; Aberdeen Proving Ground, Maryland 21010;
zUS. Army Physical Fitness School, Fort Benning, Georgia 31995.
ABSTRACT. Knapik, J., S. Darakjy, S.J. Scott, KG. Hauret, S. ing applied in an inadequate and inconsistent manner.
Canada, R. Marin, W. Rieger, and B.H. Jones. Evaluation of a As a consequence, the U.S. Army Physical Fitness School
Standardized Physical Training Program for Basic Combat was given the task of developing a standardized, prescrip-
Training. J: Strength Condo Res. 19(2):246-253. 2005.-A control
group (CG, n = 1,138) that implemented a traditional Basic tive physical training program for BCT that was modeled
Combat Training (BCT) physical training (PT) program was
on the Physical Readiness Training Program but also
compared to an evaluation group (EG, n = 829) that imple- took the Training and Doctrine Command leadership conmented
a PT program newly designed for BCT. The Army Physsiderations into account. The U.S. Army Center for
ical Fitness Test (APFT) was taken at various points in the PT Health Promotion and Preventive Medicine was request-
program, and injuries were obtained from a medical surveillance ed to evaluate this program after it had been imple-
system. After 9 weeks of training, the proportion failing the mented.
APFT ,vas lower in the EG than in the CG (1.7 vs. 3.3%, p =0.03). The purposes of this paper are to (a) describe this
After adjustment for initial fitness levels, age, and body standardized physical training program and (b) compare
ma..ors index, the relative risk of an injury in the CG was 1.6 (95%
confidence interval [CI] =1.2-2.0) and 1.5 (95% CI = 1.2-1.8)
a group of BCT recruits engaged in the new standardized
times higher than in the EG for men and women, respectively.
program to a group of recruits using a traditional BCT
The newly designed PT program resulted in higher fitness test physical training program using physical fitness, injurieR.
pass rates and lower injury rates compared to a traditional BCT and attrition as the outcome measures.
physical training program.
KEY WORDS. Injury, attrition, military personnel, aerobic fitness,
muscle contraction
METHODS
Experimental Approach to the Problcm
The design of program evaluation was quasi-experimen-
INTRODUCTION~
hysical ment of fitness soldiering. is a Military necessary historians and critical have ele- retal
comparing a control group (CG) to an evaluation group
(EG). The CG conducted a traditional physical training
program and consisted of 5 BCT companies with a total
of 656 men and 482 women at the start of the 9-week
peatedly emphasized the importance of a high BCT cycle. The EG implemented the standardized phys-
level
tasks
of physical capability for
that soldiers are required
the occupational
to perform {3,
ical training program and consisted of 5 BCT companies
with a total of 486 men and 343 women at the start of
20, 21). New recruits entering the U,S. Army are provided the BCT cycle.
regular physical training as
their general physical fitness.
an initial
However,
step to increasing
physical training
Implementation of the new standardized physical
training program in the EG proceeded in 3 major phases:
has also been shown to be associated with a high rate of (a) train the trainer, (b) pilot, and (c) evaluation. The
injury (5,6, 9, 29), an outcome that erodes the benefits of train-the-trainer phase involved 16 hours of instruction
physical training. To counter negative effects of over- given to the training cadre of the EG by the U.S. Army
training, recent efforts to reduce injuries have focused on Physical Fitness School. Fitness School personnel consid-
modifications in
13, 27).
In a previous
the physical
study, we
training
reported
program itself (9,
on a modified physered
feedback from the drill sergeants after each training
session and modifications were made to the training program
based on this feedback. An additional 4 hours were
ical training program for Basic Combat Training (BCT) spent integrating the physical training schedule into the
called
ness
Physical
Training
Readiness
was shown
Training
to reduce
(13). Physical
injuries and
Readi-
improve
BCT curriculum.
The pilot phase involved an entire 9-week BCT cycle
fitness to a greater extent than the traditional BCT phys- in which the drill sergeants from the EG implemented the
ical training program. But concern over the Physical exercises as they had been taught during the train-the-
Readiness
the Army
Program
Training
was expressed by the
and Doctrine Command
leadership of
because of the
trainer session. Personnel from the Fitness School frequently
visited, observed training, and had working
cost and
potential
logistics
problems
associated with required equipment
with some of the exercises. The
and
Train-
group sessions with the drill sergeants. Training was further
modified during the pilot phase based on drill sering
and Doctrine Command leadership also thought that geant feedback and Fitness School observations.
the Army field manual on physical training (22) con- During the evaluation phase, the Training and Doctained
most of the necessary principles for enhancing fittrine Command leadership requested that the U.S. Army
ness and reducing injuries, but these principles were be- Center for Health Promotion and Preventive Medicine as-
246

'ifi"
'..." .;
~~,,~;:
'if;:
:
, PROGRAM FOR BASIC COMBAT TRAINING 247
.c'c"
TAm.B 1. Pbysi~F~~ngprogram of the evaluation group
(further details can~:pbtairted from Knapik et al. [11]*).
Exercise
Conditioning drill 1.
Bend-and-reach
Rear lunge
High jumper
Rower
Knee-bender
Windmill
Forward lunge
Prone row
Supine bicycle
Push-up
Conditioning drill 2
Push-up
Sit-up
Pull-up
Movement drills
Verticals
Laterals
Sh\lttle sprints
Ability group running
Speed running
Stretching drills
Groin stretch
Calf stretch
Hamstrinlt stretch
Thigh stretch
Hip-nrea strctch
Ovcrhcnd arm pull
Tum-nnd.rcltch
Hip ncxor Rtrctch
Exwnd-and-flcx
Single lcg-

,
Week
;~
\~:~
c
D
30:.60
6:
30:.60
4
30:60
4
30:60
ETAL.
Week 2
first number in each cell represents the number of repetitions, and the second number
3 Week 4-- Week 5 Week 6 Week 7
WeekS \Veek 9
repetitions of each exercise were performed, and trainees Outcome Measures
progressed to 10repetitions.
Standard conditioning drill 2 consisted of 3 exercises
desigI1ed to develop upper-body strength and endurance,
Exercises included push-ups, sit-ups, and pull-ups performed
in the sequence listed. Push-ups and sit-ups were
perfornled in cadence starting with 54-count repetitions
and progressing over time to 20 4-count repetitions. Pullups
were performed in cadence for 52-count repetitions
using spotters and progressing to 52-count repetitions
unassisted.
Standard movement drills involved 3 exel"Cises designed
to assist the trainees In maneuvering their bodies
through space in unusual ways and to assist them in developing
motor efficiency. Movement drills included verticals,
laterals, and shuttle sprints performed over a distance
of about 25 yards. At se.lcctcd points in the training
program, trainees penormed a 300-yard shuttle run in
which they lined up in ranks,ran 25 yards, touched a line
on the ground with their hand, andrcturned to the starting
point, where they touched the start/finish line. This
was 1 repetition. Trainees penormed a total of 6 shuttle
run repetitions in a single bout,
Standard ability gI'oup l'Unning was llsed to develop
cardiorespiratory endurance. Ability groups were 4 aggregates
of trainees with similar run speeds as determined
by a I-mile test taken at the start of training.
Speeds and distances were progressively increased
throughout training on a predetermined schedule, shown
in Table 2. Besides long-distance running, speed running
(interval training) \vas used to develop anaerobic capacity
and faster running speeds. At the start of training, speed
running involved 4~6 sprint repetitions (depending on
ability group) at a work:rest ratio of 1:2 (run:walk). The
number of repetitions was gradually increased to 10 over
the course of BOT, and the duration of the work cycle was
increased from 30 to 60 seconds. Details of the speed running
progression are shown in Table 3,
Standard stretching drills (Table 1) were part of the
cool-down and were designed to assist trainees in controlling
postexercise stiffness, Stretching drills involved
static stretches that \'{ere each held for 30 seconds.
Stretching drills conducted at the conclusion of physic~l
training on cardiovascular days included the groin
stretch, calf stretch, hamstring stretch, thigh stretch, and
hip-area stretch. Stretching drills conducted at the conclusion
of physical training on muscle strength/endurance
days included the overhead arm pull, the turn and reach,
hip flexor stretch, the extend-and-flex, and the single legover.
Ol1ctcome measures selected for this program evaluation
included assessments of physical fitness, injuries, and attrition.
All outcome measures were obtained from existing
data sources routinely maintained by other organizations.
Physical Fitness. Two types of physical fitness tests
were employed. The first type was the Initial Fitness Assessment
consisting of a 1-minute maximal effort pushup
event, a I-minute maximal efl'ort sit-up event, and a
I-mile run for time. The Initial Fitness Assessment was
administered to recruits \vithin 1-3 days of arrival at the
BOT unit. The second type of fitness test was the Army
Physical Fitness Test (APIi'T), consisting of n 2-minut

Time between events was no less than 10 minutes and no
more than 20 minutes.
Injuries. Injuries were obtained from the Anny Medical
Surveillance Activity that warehouses data from the
Standard Ambulatory Data Record (SADR), which contains
all outpatient medical visits made by Army personnel.
Each time a trainee saw a medical care provider at
the Troop Medi24). For all categorical variables, simple contrasts
with a baseline variab]e (dcfined with a risk ratio
of 1.00) were used.
RESUI..TS
1'he physical characteristics of the CG and EG are sho\vn
in Table 4. ,!'he groups were very similar on all physical
characteristics. At the start of BCT, the proportion of
women in the CG was 42.4%, while that of the EG \vas
41.4rk (p = 0.66). At the conclusion of training, the proportion
of women in the CG was 39.9%, \vhile that of the
EG was 37.8"/c, (p = 0.40).
Physical Fitness Outcomes
Table 5 shows the Initial Fitness Assessment scores of the
2 groups. Men and women in the EG performed an average
of 2 more push-ups in a minute than those in the
CG, and this difference was statistically significant.
There were no group differences on sit-ups or the 1-mile
run.
Table 6 shows the APFT scores of the CG and EG at
weeks 5 and 7. Since there were initial group differences
on push-ups (Table 4), ANCOV A was used for analysis of
this test event with adjustment for push-up scores on the
Initial Fitness Assessment. The ANCOVA showed no significant
group-by-week interaction (p = 0.13 for men, p
= 0.58 for \vomen). There was an improvement from \veek
5 to week 7 (p < 0.01 for both men and women). The EG
demonstrated higher push-up performance than the CG
(p < 0.01 for men and p = 0.02 for women). Overall, the
results indicate that for both men and women, push-up
performance of the EG was higher than that of the CG at

'..,
~"
:;f~_t
ETAL.
.p value compares CG and EG using an independent-samples i-test.
t BM! = body mass index.
TABLE 5. Comparison of Initial Fitness Assessment scores of
the control group (CG) and the evaluation group (EG).
Men Women
Push-tipS CG
(/I) EG
Sit-ups CG
(/II EG
I-mi. run CG
(min) EG
28
30
31
31
8.4
8.4
1.1
1.1
7
7
1.2
1.4

Incidence
rate
(injuries!
1,000
trainee-days)
5.223.41
p value*
Incidence
rate
(injuries!
1,000
trainee-days) p value.
CO
9.24 0.04
EO
7.22
.Compares CO and EG using a chi-square test. for incidence
rates (I),
TABLE 9. Comparison of relative injury risk in the control
;;"mp (CG) and the evaluation group (~~) (from Cox regression).
Multivariatet
1.29-2.091.21-1.82
Men
Women
Men
Women
~. From Wald statistic.
"'" t.'Iultivariatc modcl includes age, body mass index, and lniti..IJ
Fitncfifi Assessment variables.
TARLK 10. Comparison of attrition (dischargcs and newstarts)
in the control ""roup (CG) find the cvaluntion group (EG).
Attrition Altrition
(~,) p vmue* (~,) p vmu(!*
retakes, but this was statisticalLy significant only after all
-retakes had been completed.. Likewise, the EG women
had a higher APFT pass rate throughout, but this was
statistically significant only at weeks 5 and 7. When men
and women were combined, the proportion of recruits
passing the APFT was higher for the EG than for the CG
at all test periods.
Injury Outcomes
Table 8 shows the person-time injury incidence rates for
the 2 groups. For both men and women, injury incidence
rates were significantly higher in the CG than in the EG.
Table 9 shows the univariate and multivariate Cox regression
results. Injury risk was higher in the CG than
in the EG for both univariate and muLtivaz;ate analyses.
Attrition Outcomes
1.21-1.98
1.l.~1..82
Table 10 shows the proportion of recruits who did not
complete BOT with their peers during the 9-\veek BOT
cycle. There were no significant differences between the
CG and EG.
DISCUSSION
PROGRAM FOR BASIC COMBAT TRAINlKG 251
The EG recruits who trained according to the new standardized
physical training program had more favorable
training outcomes than the CG recruits who used a traditional
physical training program. The EG had lo,ver injury
risk, a higher APFT pass rate at week 7, and a higher
APFl' pass rate after all APFl' retakes had been completed.
There were no significant group differences in attrition.
The EG demonstrated higher push-up perfolmance
than the CG at weeks 5 and 7, even after correction for
the higher initial scores of the EG. A previous BCT physical
training investigation evaluated a program similar to
the one tested here (13) but \vith less emphasis on pushup
training. In that previous evaluation, the push-up performance
of the group using a special training program
was lower than that of a group using a traditional physical
training program. In the present evaluation. more
emphasis was placed on push-up training, and this may
have accounted for the higher push-up performance of the
EG. There were some group differences on sit-ups and the
2-mile run on week 5, but by week 7 the performances of
the 2 groups were similar.
In consonance with our previous investigation (13),
the similar 2-mile run performances of the EG and CG at
week 7 appears to have been achieved with fewer total
running miles on the part of the EG. In the present pro.
gram evaluation, total running mileage in the CG was
estimated from the training schedules that were kept by
the individual companies. The EG had mandated running
distances that required strict adhcrence. Total running
distances during BCT for the fastest and slowest of the 4
ability groups in the EG were 39 and 26 miles, respectively.
Total running mileages of the CG were 44 and 34
miles, for the fastest and s1owest abi1ity I,7fOUPS, respectively.
Thus, the slowest EG ability group ran an estimated
8 fewer miles (31i>f, less) than the slowest CG; the
fastest EG ability group ran an estimated 5 fewer miles
(13% less) than the fastest CG. Speed running performed
by EG trainees probably assisted in improving APFT 2mile
run speed in light of this reduced total running mileage.
Speed running is referred to as interval training in
general exercise physiology literature (4, 30). Inter\'al
training has been shown to result in greater improvements
in running speed than long-distance running
alone, especially in initially sedentary and recreationally
active individuals (17).
Person-time injury incidence rates and the univariate
analysis of injury risk by Cox regression all showed lower
injury rates and risks in the EG compared to the CG.
Even when age, BMI, and initial fitness were included in
a multivariate analysis, the EG still had lower injulJ' risk.
This is in general agreement with our previous investigation
(13). The lower injury rates in the EG may be associated
with certain characteristics of the physical training
program that include (a) a lower total amount of running;
(b) the gradual, progressive introduction of exercise
stress; and (c) the greater variety of exercise in the program.
As noted previously, the EG ran fewer miles than
the ca. Numerous studies have demonstrated an association
between higher injUl'Y rates and longer running
distances (5, 15, 16, 18, 24, 27, 29). Studies in Army,
Navy, and Marine basic training have demonstrated that
groups with lower running mileage have lower injury

~~'~~
"'c.t~~
ET:AI
In run test times com-
.distances (5, 27, 29).
". "c.c speed running was a key feature
ofthestandardizeq;...physical training program. A number
of studies (12, 13.,c~~., 26) have suggested that increased
time devoted toin~rval traini~g and decreased time devoted
to distance ~nning is ~ssociated with less likelihood
of injuries in BOT, possibly because less total distance
is run (5). However, all these previous studies (12,
13, 23, 26) were confounded with multiple interventions,
making it difficult to determine the influence of interval
training alone on injUI"y risk.
Another feature of the new ph)'sical training program
that may have influenced injury rates was the gradual
introduction of the exercises following the principle of
The data here also reinforce the importance of following
basic principles of exercise prescription (19, 30) when
individuals are starting a new exercise program. In BCT,
it is not possible to tailor exercise programs to individual
needs because of the large number of trainees, the limited
number of trainers, and the requirement to maintain control
of personnel at all times. However, it is possible to
tailor programs to grOllpS of individuals with similar fitness'levels
\vho can exercise together. Because many individuals
are relatively sedentary on arrival at BCT, the
program must start gradually and progress to higher exercise
intensities over time. A high vo]ume of running is
not necessary to improve aerobic fitness; inc]uding more
interval training may assist in reducing running mileage
(high mileage is associated with high injury incidence)
progressive overload (19), Training drills performed by while enhancing aerobic fitness,
the EG were initiated slowly, and the number of repetitions
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PROGRAM FOR BASIC COMBAT TRAINING 253
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