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Int. J. Environ. Res. Public Health 2022, 19, x. https://doi.org/10.3390/xxxxx www.mdpi.com/journal/ijerph
Article
Assessment of Energy Expenditure of Police Officers Trained
in Polish Police Schools and Police Training Centers
Jerzy Bertrandt
1,
*, Anna Anyżewska
2
, Roman Łakomy
3
, Tomasz Lepionka
3
, Ewa Szarska
3
, Andrzej Tomczak
4
,
Agata Gaździńska
5
, Karolina Bertrandt-Tomaszewska
3
, Krzysztof Kłos
6
and Ewelina Maculewicz
7
1
Faculty of Economic Sciences, John Paul II University of Applied Sciences in Biała Podlaska, Sidorska 95/97,
21-500 Biała Podlaska, Poland
2
University of Economics and Human Sciences in Warsaw, Okopowa 59, 01-043 Warsaw, Poland;
a.anyzewska@vizja.pl
3
Department of Hygiene and Physiology, Military Institute of Hygiene and Epidemiology, 4 Kozielska,
01-163 Warsaw, Poland; roman.lakomy@interia.pl (R.Ł.); tomasz.lepionka@wihe.pl (T.L.);
eszarska@gmail.com (E.S.); karolinabertrandt@gmail.com
(K.B.-T.)
4
Independent Researcher, 02-348 Warsaw, Poland, biuro.at@onet.pl
5
Department of Psychophysiological Measurements and Human Factor Research, Military Institute of Avia-
tion Medicine, 54/56 Krasinskiego, 01-755 Warsaw, Poland; afrotena@gmail.com
6
Department of Infectious Diseases and Allergology, Military Institute of Medicine, Szaserów 128,
04-141 Warsaw, Poland; kklos@wim.mil.pl
7
Faculty of Physical Education, Jozef Pilsudski University of Physical Education in Warsaw, 34 Marymoncka,
00-809 Warsaw, Poland; ewelina.maculewicz@awf.edu.pl
* Correspondence: jwbertrandt@gmail.com
Abstract: Knowledge of the energy expenditure related to the training of policemen allows for as-
sessment of the intensity of the work performed and is an indispensable element of planning and
implementing nutrition. This study on energy expenditure comprised a total of 280 persons, stu-
dents of two Polish police schools and two police training centers. The energy expenditure of
policemen was determined based on measurements of the heart rate using Polar RC3 GPS heart
rate monitors. The energy expenditure of policemen associated with the training process in the
police schools and training centers ranged from 1793 to 3043 kcal/8h and amounted to 2314 ± 945
kcal/8h during training on average. The values of energy expenditure related to a typical training
day in Polish institutions conducting police training are diverse and depend on the specificity and
nature of the training. According to the criteria for assessing the burden of work, the work per-
formed by police officers can be classified as hard work and very hard work.
Keywords: energy expenditure; police schools; police officers; physical activity; hardness of work
1. Introduction
Many studies have concluded that physical inactivity is a primary cause of most
chronic diseases [1–3]. The benefits of physical activity for maintaining health have been
well documented, especially in the prevention and treatment of chronic diseases such as
certain cancers, type 2 diabetes, and cardiovascular diseases [4,5]. This is especially im-
portant in the police force, as law enforcement officers are often required to adapt quick-
ly from sedentary, passive functions to hostile environments where maximum body
effort is needed [6]. In this context, accurate measurement of energy expenditure is es-
sential for both epidemiological studies and assessment of human nutritional needs
[7,8].
Total energy expenditure is the energy required by the body during a 24-h period
and is determined by the sum of three components: basal energy expenditure, diet-
induced thermogenesis, and physical activity [9]. Determination of energy expenditure
Citation: Bertrandt, J.;
Anyżewska, A.; Łakomy, R.;
Lepionka, T.; Szarska, E.;
Tomczak, A.; Gaździńska, A.;
Bertrandt-Tomaszewska, K.;
Kłos, K.; Maculewicz, E. Assessment
of Energy Expenditure of Police
Officers Trained in Polish Police
Schools and Police Training Centers.
Int. J. Environ. Res. Public Health 2022,
19, x. https://doi.org/10.3390/xxxxx
Academic Editor: José Carmelo
Adsuar Sala
Received: 11 April 2022
Accepted: 1 June 2022
Published: date
Publisher’s Note: MDPI stays
neutral with regard to jurisdictional
claims in published maps and
institutional affiliations.
Copyright: © 2022 by the authors.
Submitted for possible open access
publication under the terms and
conditions of the Creative Commons
Attribution (CC BY) license
(https://creativecommons.org/license
s/by/4.0/).
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 2 of 11
is important to adjust the nutritional habits of individual people and must take into ac-
count the energy requirements for physical activity and specific health conditions. To
date, no research has been conducted in Poland on the energy burden associated with
the service and training of officers studying at police schools and trained at police train-
ing centers. In the Polish uniformed services, such research was conducted only among
students of various types of military schools and fire schools. These studies indicate that
students at military universities were burdened with an energy expenditure of 3339 to
4121 kcal/d, while students at fire schools—from 3735 to 4745 kcal/d [10–13]. According
to the workload classification by Lehman, they performed medium to very heavy work
[14].
The issues related to energy expenditure, the energy value of food, and, conse-
quently, the systemic energy balance are of particular importance in the uniformed ser-
vices. Knowledge of the physical burden connected with the specificity of the service
performed should be an indispensable element of food planning, which must cover the
energy needs of the body and provide all necessary nutrients in the right amounts and
proportions. The police are a uniformed and armed formation serving the public and in-
tended to protect human security and to maintain public safety and order. Knowledge of
the energy expenditure related to the training of police officers allows for assessment of
the severity of work performed and provides a possibility to quantify it and forms the
basis for establishing nutrition standards. The heaviness of work, the measure of which
is the value of energy expenditure, is an indispensable element of an assessment of phys-
ical load in accordance with psychophysical capabilities, while the physical load is a re-
lation between the requirements of work based on physical effort and the capabilities of
the body.
The aim of this study was to determine the energy expenditure of students at police
schools and police training centers in relation to the specificity and nature of the training
to assess degree of intensity of their work.
2. Materials and Methods
2.1. Participants
The research on energy expenditure covered 270 students at four police training in-
stitutions: two police schools, a police training center, and a police prevention depart-
ment.
The examination of energy expenditure covered 280 persons trained in 2 Polish po-
lice schools and 2 police training centers. The research involved 60 students at the police
academy, including 50 men and 10 women; 113 students, all men, trained on specialist
courses at the police training center; 47 students at the police school; and 60 policemen
trained at the police prevention department.
Due to the small number of women studying in police schools and police training
centers, only men took part in the research. Thus, the study covered 50 students of the
police academy, 113 students trained in specialist courses at the police training center, 47
students at the police school, and 60 students at the police prevention department.
Among the 113 students of the police training center, 74 people were trained on a spe-
cialist course for police officers intervening against aggressive and dangerous persons,
18 participated in training for future police dog handlers, and 21 were trained to work in
the water police. All students participated in the same theoretical classes and classes on
the use of weapons, while the other specialist classes took into account the specificity of
the future service in the police.
The research on the students of the police academy and the police school was con-
ducted during typical training activities included in the training plan and covered both
theoretical classes in the form of lectures and those related to high physical activity, such
as tactics or shooting.
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 3 of 11
The research was conducted in accordance with the Helsinki Declaration of the
World Medical Association and was approved by the Ethics Committee of the Military
Institute of Hygiene and Epidemiology (no. 1/XXI 95/2016). Participants received an in-
formation sheet about the details of the study, the purpose, and the procedures used as
well as potential risks and benefits of their participation.
2.2. Measurement of Height and Weight
Body height (without shoes) was measured using a portable stadiometer (TANITA
HR-001, Tanita Corporation, Tokyo, Japan). Body weight was measured using a bioelec-
trical impedance analysis (BIA) with the TANITA MC-780 103 device (Tanita Corpora-
tion, Tokyo, Japan), with an accuracy of 0.1 kg, according to the procedure specified in
the instruction manual (lightly dressed, without shoes). All measurements were per-
formed according to the procedure specified in the instruction manual and without any
metal objects.
2.3. Measurement of Energy Expenditure
The method of analyzing heart rate changes was used to measure energy expendi-
ture. The energy expenditure study included heart rate measurements with a Polar RC3
GPS heart rate monitor (Polar Electro Oy, Kempele, Finland). The values of energy ex-
penditure of the activities performed by the policemen constitute the average value of at
least three measurements. The obtained results were the basis for determining the ener-
gy demand of policemen in relation to the specificity and nature of training and/or ser-
vice, as well as for the assessment of the intensity of work, in accordance with the classi-
fication given by Lehman (Table 1) [14].
Table 1. Classification of work severity on the basis of energy expenditure values for an 8-h work-
ing day [6].
Severity of Work
Energy Expenditure during an 8-h Working Day
Male Female
kcal kJ kcal kJ
Very light <300 <1256 <200 <837
Light 300–800 1256–3350 200–700 837–2930
Moderate 800–1500 3350–6280 700–1000 2930–4187
Hard 1500–2000 6280–8374 1000–1200 4187–5024
Very hard >2000 >8374 >1200 >5024
2.4. Statistical Analyses
All statistical analyses were performed using the program R (The R Foundation for
Statistical Computing v2.0–1. https://cran.r-project.org (accessed on 20 September 2021)).
Anthropometric data are shown as mean values ± standard deviation, and differences
among experimental groups were analyzed with Student’s t-test, which were statistically
significant when p < 0.05. To check the compliance of the variables with the normal dis-
tribution, the Shapiro–Wilk test was used, and Levene’s test was used for verification of
the homogeneity of variance. The differences in the values of energy expenditure of stu-
dents at individual universities and training centers were calculated using the chi-square
test. The data spread is presented in interquartile range (IQR) values.
3. Results
3.1. Characteristics of the Studied Groups
The characteristics of the studied groups are given in Table 2.
Table 2. Characteristics of police officers.
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 4 of 11
Students of the Police Acad-
emy
Students of the Police
Training Center
Students of the Police
School
Policemen Trained in
the Police Prevention
Department
Sex Male—50 Male—113 Male—47 Male—60
Age (years) 38.0 ± 6.7
(IQR = 4.0)
39.8 ± 9.8
(IQR = 9.0)
40.2 ± 6.6
(IQR = 11.0)
36.1 ± 6.6 *
(IQR = 8.0)
Height (cm) 178.3 ± 8.3
(IQR = 7.0)
179.4 ± 8.6
(IQR = 11.0)
180.4 ± 6.9
(IQR = 9.0)
180.3 ± 6.5
(IQR = 9.0)
Weight (kg) 81.7 ± 13.3
(IQR = 16.5)
87.7 ± 13.6
(IQR = 19.6)
93.8 ± 15.3 *
(IQR = 15)
83.7 ± 12.5
(IQR = 16.0)
* Statistically significant difference at p < 0.05. IQR—interquartile range.
In the police academy, the research included students of the police service prepara-
tion course.
The group of people trained in the police prevention department was the youngest,
which resulted from the student selection criteria, while students at the police school
were characterized by the highest body weight.
3.2. Energy Expenditure of Police Academy Students
The study of students’ energy expenditure was carried out during the implementa-
tion of tasks in the study program at the police academy. It included measurements both
during typical theoretical classes and in field conditions, during which students learned
how to use weapons, arrest procedures, chase, etc. The results of the energy expenditure
of police officers carrying out typical training tasks during 8 h of training are presented
in Table 3.
Table 3. Average energy expenditure of men studying in the police academy during an 8-h train-
ing day.
N = 50 Lectures, Tactics Classes, Detention (Handcuffing), Physical Education Classes
X ± SD Median Min Max IQR
Time (h) 9.5 ± 2.5 9.4 5.6 25.2 0.8
kcal/h 279 ± 68 261 141 441 92
Energy expenditure kcal/min 4.65 ± 1.13 4.35 2.35 7.35 1.5
kcal/h/kg bw 3.3 ± 0.9 3.2 1.3 5.4 1.1
kcal/min/kg bw 0.055 ± 0.014 0.052 0.022 0.09 0
kcal measured 2646.8 ± 1007.7 2602.5 1461 5117 1016
Max 169.4 ± 24.7 170.5 93 220 32.0
Pulse Min 59.5 ± 11.8 61 47 77 11.0
Average 92.6 ± 8.2 94 68 108 12.0
Average kcal/8 h 2233 ± 546 2247 1127 3527 736
IQR—interquartile range.
Analysis of the obtained results showed that the average energy load of police of-
ficers carrying out training tasks at the basic course in the police academy amounted to
2233 ± 546 kcal/8 h and varied depending on the activities performed. This value, ac-
cording to Lehman’s classification of workload, allows to classify the work performed as
very heavy work [6].
3.3. Energy Expenditure of Students at the Police Training Center
3.3.1. Energy Expenditure of Students Trained on Specialist Courses for Police Officers
The research on energy expenditure covered 74 men, all students at the police train-
ing center trained on specialist courses for police officers intervening against aggressive
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 5 of 11
and dangerous people and for instructors of police shooting in anti-terrorist police units.
The mean body weight and mean height of the officers were 90.4 ± 13.8 kg and 179.7 ±
7.8 cm, respectively. The energy expenditure of police officers trained for the above-
mentioned specialist courses included both training tasks of a theoretical nature (lec-
tures) and those related to high physical activity, e.g., preparation and implementation
of shooting. The results of the energy load of officers in relation to the training process
are summarized in Table 4.
Table 4. Energy burden related to implementation of training at specialist courses at the police
training center.
N = 74
Police Training Center
X ± SD Median Min Max IQR
Energy expendi-
ture
Time 6.3 ± 1.1 6.3 1.8 7.6 0.47
kcal/h 299.9 ± 74.4 299.6 105.2 460.6 96.14
kcal/min 4.99 ± 1.24 4.99 1.75 7.67 1.60
kcal/h/kg bw 3.4 ± 1 3.1 1.4 6.3 1.31
kcal/min/kg bw 0.056 ± 0.016 0.052 0.023 0.102 0.02
kcal measured 1889.8 ± 964.7 1884.5 656 3402 683
Pulse/min
Maximum 166 ± 28 170 47 232 34
Minimum 61 ± 103 52 32 89 11
Average 97.1 ± 9.3 94 83 125 12
Average kcal/8 h 2458 ± 723 2242 1010 4546 769.1
IQR—interquartile range.
It was shown that the average energy expenditure of an officer associated with a
typical 8-h day of program training was 2458 ± 723 kcal, which places the work per-
formed in the category of very heavy work. It should be emphasized that there is a large
variation in the results of energy load related to the implementation of various types of
training. Theoretical training resulted in a low energy load of students, amounting to
1.75 kcal/min, which was characteristic of light work, while during intensive tactical
classes, it amounted to 7.67 kcal/min, indicating the performance of hard work.
3.3.2. Energy Expenditure of Officers Trained as Future Service Dog Handlers
Another assessment concerned the energy expenditure of officers trained as future
service dog handlers. The study involved 18 officers, aged 34 ± 4.3 years, of an average
body weight of 83.2 ± 16.0 kg and body height of 174.0 ± 7.0 cm. The training included
training of patrol dogs and dogs for special tasks such as searching for drugs or explo-
sives. The results of the energy expenditure of service dog handlers are summarized in
Table 5.
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 6 of 11
Table 5. Energy load related to the training of officers—future service dog handlers.
N = 18 Training Center for Service Dog Handlers for the Police
X ± SD Median Min Max IQR
Energy
ex-
pendi-
ture
Time (h) 5.3 ± 1.3 5.6 0.8 6.1 0.5
kcal/h 263.8 ± 104.2 263.7 1388.4 448.7 213.87
kcal/min 4.39 ± 1.73 4.39 2.30 7.47 3.56
kcal/h/kg bw 3.10 ± 1.00 3.10 1.60 5.60 1.34
kcal/min/kg bw 0.052 ± 0.017 0.052 0.026 0.092 0.02
kcal measured 1422 ± 727 1299 212.0 2737 1441
Pulse/
min
Maximum 56.4 ± 24.4 152,0 126.0 228.0 37
Minimum 60.0 ± 11.0 63.0 39.0 75.0 13
Average 94.0 ± 9.8 96.0 78.0 109.0 19
Aver-
age kcal/8 h 2111 ± 834 2110 1107 3590 857.98
IQR—interquartile range.
The energy expenditure related to the training of service dog handlers amounted to
2111 ± 834 kcal/8 h, which puts the severity of work performed in the category of very
heavy work.
3.3.3. Energy Expenditure of Police Officers Who Perform Tasks on Waters
The police training center trains, among others, police officers who perform tasks
on waters and in surrounding areas. During these courses, students acquire skills related
to performing specialized tasks in the preventive service on water; rescuing and search-
ing for people, property, and floating equipment; and maneuvering a boat in difficult
and extreme weather conditions. They also acquire skills in organizing rescue opera-
tions, handling specialized rescue and navigation equipment, and learning to use mod-
ern means of transport, including water scooters, while on patrol. The training process
takes place mainly on water and concerns driving and operating motorboats and naviga-
tion and rescue operations in water areas.
The study of energy expenditure of police officers connected with the specificity of
this training covered 21 male officers, aged 34.5 ± 6.6 years, with an average body weight
of 89.5 ± 10.9 kg and height of 184.5 ± 4.5 cm. The values of energy load associated with
the training are summarized in Table 6.
Table 6. Energy burden of officers related to the training of policemen performing tasks on water.
N = 21 Training of Policemen Performing Tasks at the Water Areas
X ± SD Median Min Max IQR
Energy expenditure
Time (h) 6.0 ± 0.0 6.0 6.0 6.0 0.13
kcal/h 221.7 ± 69.1 230.9 108.7 415.8 63.14
kcal/min 3.69 ± 1.73 3.84 1.81 6.93 1.05
kcal/h/kg bw 2.5 ± 0.9 2.5 1.3 5.1 1.07
kcal/min/kg bw 0.042 ± 0.014 0.041 0.021 0.085 0.02
kcal measured 1433.6 ± 441.9 1470.0 712.0 2668.0 387
Pulse/min
Maximum 144.7 ± 20.8 143.0 113.0 192.0 23
Minimum 60.0 ± 10.0 58.0 43.0 81.0 11
Average 85.4 ± 10.7 87.0 65.0 107.0 9
Average kcal/8 h 1973 ± 553 1847 870 3326 505.12
IQR—interquartile range.
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 7 of 11
It was shown that an 8-h day of training resulted in an energy load of 1973 ± 553
kcal, indicating that they were performing heavy work. The relatively low energy ex-
penditure of the water police trainees compared to those participating in other courses
results from the specificity of patrolling water areas on motorboats, which is related to
their low physical activity. Analysis of the average values of energy expenditure in-
curred by officers during the 8-h training process in the three centers included in the po-
lice training center showed that officers were burdened with different levels of energy
expenditure, which resulted from the specificity of the training. The highest value of en-
ergy load related to the 8-h training day was found in officers trained on specialist
courses and during the training of service dog handlers, which qualified the work as
very hard work, while officers trained on water performed heavy work.
3.4. Energy Expenditure of Policemen Trained in the Police School
The police school specializes in training prevention police officers, i.e., those whose
service has a direct impact on public order and the sense of security of citizens. Among
other things, the school provides basic vocational training that every police officer ad-
mitted to the service must undergo. It prepares them for the implementation of tasks in
basic executive positions (e.g., in patrol and intervention services, in police prevention
units, or in a convoy service). Students gain knowledge and skills in the fields of law,
crime prevention, forensics, intervention tactics and techniques, psychology, social
communication, ethics, human rights, first aid, shooting training, and operation of IT
and communication equipment. They learn how to perform patrol intervention and
convoy protection services as well as the specifics of work as a district policeman and
unit officer on duty.
A total of 47 male officers with an average body weight and height of 93.8 ± 15.3 kg
and 180.4 ± 6.9 cm, respectively, were included in this energy expenditure study.
The results of the research on the energy load of officers during the 8-h training day
are summarized in Table 7.
Table 7. Energy expenditure of male officers trained at the police school.
N = 47 Training of Policemen at the Police School
X ± SD Median Min Max IQR
Energy expenditure
Time (h) 7.0 ± 2.70 6.5 2.5 24.0 1.5
kcal/h 283.0 ± 118.0 292.0 54.0 552.0 166.6
kcal/min 4.71 ± 1.96 4.86 0.90 9.20 2.8
kcal/h/kg bw 3.0 ± 1.2 2.8 0.7 5.7 2.0
kcal/min/kg bw 0.050 ± 0.020 0.047 0.011 0.095 0
kcal measured 1976.0 ± 947.0 1982.0 345.0 4930.0 1248
Pulse/min
Maximum 159.6 ± 27.8 155.0 115.0 224.0 28
Minimum 66.2 ± 11.2 66.0 27.0 83.0 16
Average 92.9 ± 11.4 93.0 66.0 116.0 16
Average kcal/8 h 2267 ± 942 2334 936 4415 1332.6
IQR—interquartile range.
The results of the research on the energy expenditure of officers trained in the po-
lice school show that the work performed during the training is very hard work.
3.5. Energy Expenditure of Policemen Trained in the Police Prevention Unit
Police prevention units are designed mainly for team activities within compact
subunits. The main tasks of these units include the following:
- Protection of public security and order during legal gatherings and mass events;
- Restoring public order in the event of collective violation of the law;
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 8 of 11
- Protection of public order in the event of constitutionally defined states of emergen-
cy as well as catastrophes and natural disasters;
- Pursuit of dangerous criminals.
The study involved 60 officers with an average body weight of 83.7 ± 12.5 kg and an
average body height of 180.3 ± 6.5 cm. The research included activities carried out on a
typical training day, including combat tactics, drills, and shooting.
The obtained results are summarized in Table 8.
Table 8. Energy expenditure of officers trained in the police prevention unit.
N = 60 Training of Policemen at Police Prevention Unit
X ± SD Median Min Max IQR
Energy expenditure
Time (h) 5.7 ± 1.0 6.0 2.6 7.0 0.88
kcal/h 380.0 ± 164.0 381.0 92.0 678.0 267
kcal/min 6.33 ± 2.73 6.35 1.53 11.3 4.45
kcal/h/bw 4.6 ± 1.9 4.9 1.3 8.2 3.43
kcal/min/bw 0.076 ± 0.031 0.082 0.021 0.138 0.06
kcal measured 2171.0 ± 1013.9 2170.0 244.0 4464.0 1412
Pulse/min
Maximum 172.4 ± 26.1 179.0 115.0 226.0 42
Minimum 62.9 ± 11.1 64.0 44.0 78.0 15
Average 102.7 ± 16.8 106.0 62.0 134.0 26
Average kcal/8 h 3043 ± 1308 3048 937 5427 2136
IQR—interquartile range.
It should be noted that in all examined police units, there was a large variation in
the results, from low values of 1463.0 ± 339.0 kcal/8 h in the case of women’s training up
to high values of 3043 kcal/8 h, which was connected with the specificity, conditions, and
nature of the training and service performed. The average values of energy expenditure
of the police officers trained for 8 h in all divisions are summarized in Table 9.
Table 9. Average values of energy expenditure of the police officers trained within 8 h.
N = 280 The Average Values of Energy Expenditure Related to the Training of Police Officers
X ± SD Median Min Max IQR
Energy expendi-
ture
Time (h) 7.0 ± 2.5 6.8 0.8 25.6 1.52
kcal/h 297.0 ± 118.0 287.0 54.0 678.0 146.6
kcal/min 4.95 ± 1.96 4.78 0.90 11.3 2.44
kcal/h/bw 3.50 ± 1.40 3.20 0.70 8.20 1.76
kcal/min/kg bw 0.058 ± 0.023 0.053 0.011 0.136 0.03
kcal measured 2035.0 ± 910.1 1954.0 212.0 5117.0 1118
Pulse/min
Maximum 165.4 ± 25.4 165.5 93.0 232.0 38
Minimum 62.2 ± 11.2 63.0 47.0 89.0 14
Average 95.7 ± 12.6 94.5 62.0 137.0 17
Average kcal/8 h 2314 ± 945 2294 736 5427 1173
IQR—interquartile range.
The analysis of the obtained values of energy load of the examined students in re-
lation to the training processes showed that their energy expenditure from the imple-
mentation of individual training tasks was similar and ranged from 0.42 to 0.71
kcal/min/kg bw (Table 10). Although the largest energy expenditure related to the im-
plementation of individual training activities, as well as that related to the 8-h training
process, was observed in the students of police prevention units, it was not a statistically
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 9 of 11
significant difference. On the other hand, the lowest energy expenditure related to the
training was observed in the water police.
Table 10. Differences in the value of energy expenditure related to the process and specificity of
training students at police schools and training centers.
Energy Expendi-
ture
Students at the
Police Acade-
my
Students at the Police Training Center
Students at the
Police School
Policemen Trained
in the Police
Prevention
Department
Specialist
Courses
Dog
Handlers
Water Police
Training
kcal/min/kg bw 0.055 ± 0.014 0.056 ± 0.016 0.052 ± 0.017 0.042 ± 0.014 * 0.050 ± 0.020 0.076 ± 0.031
Daily energy
expenditure
kcal/8 h
2223 ± 546 2458 ± 723 2111 ± 834 1973 ± 553 * 2267 ± 942 3043 ± 1308
Classification of
the severity of
work
Very hard work Very hard
work
Very hard
work Hard work Very hard work Very hard work
* Statistically significant difference at p < 0.05.
4. Discussion
Poland is one of the few countries where determination of the energy expenditure
of workers on tasks at work is required by law. Information on how physically demand-
ing work is (a measure of energy expenditure) at each workstation is essential not only
for comparison with applicable regulations concerning maximum allowable values for
regular work activity but also for work planning and taking proactive action to reduce
the adverse health effects of work.
The value of energy expenditure related to an 8-h work shift should be taken into
account when planning work, planning breaks, and allocating preventive meals and
drinks by the employer. Heavy workload increases the risk of musculoskeletal system
dysfunction, which is one of the causes of accelerated degenerative changes (especially
of the spine) and an accelerated decline in exercise capacity. Hard physical work should
also be considered a risk factor for cardiovascular disorders such as high blood pressure
and ischemic heart disease. The assessment of energy expenditure, and thus the severity
of work performed, allows to quantify the physical load of an employee according to
his/her endurance capabilities.
Law enforcement is a highly stressful occupation that is prone to increasing the
prevalence and incidence of cardiovascular disease. Evidence indicates that the preva-
lence of traditional cardiovascular risk factors among police officers is high (often higher
than in the general population). Police work creates exposure to risk factors for the de-
velopment of cardiovascular disease and diabetes and results in increased mortality
rates [15–17]. Epidemiological studies suggest that police officers and related public se-
curity personnel develop an increased risk of cardiovascular morbidity and mortality.
Currently employed police personnel have a high prevalence of traditional risk factors,
including hypertension, hyperlipidemia, metabolic syndrome, smoking, and a sedentary
lifestyle. Moreover, low physical activity of policemen leads to a positive energy balance
and, consequently, to obesity [18,19]. Obesity may be more common among police offic-
ers compared with civilians, whereas diabetes is present less frequently. Law enforce-
ment personnel are also exposed to occupational risk factors such as sudden physical
exertion, acute and chronic psychological stress, shift work, and noise [16]. Obesity not
only affects the ability of police officers to perform their work-related duties, but conse-
quently, it may also impact public safety.
In the available literature, there are few works concerning the energy expenditure
of students at police schools and police officers trained in police training centers. The
values of energy expenditure obtained in the present study indicate that the energy
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 10 of 11
loads of students and trainees participating in training programs in Polish police schools
and police training centers range from 1973 ± 553 to 3043 ± 1308 kcal/8 h of work. These
values place their work in the category of very hard work.
Studies in police schools can be compared to studies from fire service schools. The
results of earlier research revealed that the values of energy expenditure during typical
activities from the training program prepared for students at the Main School of Fire
Service were diverse and ranged from 1.49 to 10.66 kcal/min. According to Christensen’s
classification of work severity, the work performed by students can be classified as light
work to very heavy work [20]. The average daily energy load of students at the Main
School of Fire Service on a typical day of training on the training ground was 4745 ± 1181
kcal/d, which means that the work performed should be considered, according to the ob-
ligatory classification of work intensity, as very heavy [11].
Previous studies on the energy load of students at the National Fire Service Aspir-
ants School showed that their daily energy expenditure from the training process
amounted to 3735.5 kcal, while during 8 h of program classes, students expended only
1289.5 kcal [12].
Historical studies on the energy burden of 30 male and 10 female police cadets,
randomly selected from the Singapore Police Force, showed that the value of daily ener-
gy expenditure associated with duty and training tasks was 3028 and 1752 kcal, respec-
tively [21].
A study on the energy expenditure of 28 healthy police officers working in shifts
showed that the energy expenditure was 3062 kcal/d during night shifts, amounted to
2647 kcal/d during day shifts, and was the lowest on holiday duty, when it amounted to
2310 kcal/d [22].
An assessment of the service-related daily energy expenditure of Malaysian police
officers showed that males expended 2639.6 ± 229.4 kcal/d and females 2268.9 ± 203.5
kcal/d [23].
The values obtained in the present study on energy expenditure associated with
studies and training in Polish police schools and police training centers confirm the re-
sults of previous research, indicating that both studies and police training as well as po-
lice service are characterized by work that falls into the category of heavy work.
5. Conclusions
1. Assuming that the average value of men’s energy expenditure during the training
process in Polish police schools and the police training center, as well as in the pre-
vention unit, amounts to 2314 ± 945 kcal/8 h of training, it should be concluded that
the work performed by police officers belongs to the category of very hard work.
2. The energy expenditure related to the implementation of the study and training
program depends on the type of university or training center as well as the specific-
ity of the performed training activities.
3. The energy value of the daily food ration used in the nutrition of police officers
trained in Polish police schools and police training centers should be adjusted to
their energy expenditure.
Author Contributions: Conceptualization, J.B.; methodology, J.B. and R.Ł.; software, R.Ł. and T.L.;
formal analysis, J.B., A.A., and E.S.; investigation, J.B., R.Ł., T.L., E.M., A.A., A.T., K.B.-T., A.G.,
and K.K.; resources, J.B. and E.M.; data curation, J.B., R.Ł., A.A., E.M., and T.L.; writing—original
draft preparation, J.B.; writing—review and editing, J.B., T.L., and A.A.; visualization, J.B., K.B.-T.,
and A.T.; supervision, J.B.; project administration, J.B.; funding acquisition, J.B. All authors have
read and agreed to the published version of the manuscript.
Funding: The research was funded by the Polish Ministry of Health in 2016–2020 as part of the
National Health Program (agreement 518/2016/DA).
Institutional Review Board Statement: The procedures used in this research were conducted in
accordance with the World Medical Association’s Declaration of Helsinki, and the research proto-
Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 11 of 11
col was approved by the Ethics Committee of the Military Institute of Hygiene and Epidemiolo-
gy—resolution number 1/XXI /2016.
Informed Consent Statement: Informed consent was obtained from all subjects involved in the
study.
Data Availability Statement: The data presented in this study are available on request from the
corresponding author.
Acknowledgments: The authors sincerely thank all policemen who participated in the study.
Conflicts of Interest: The authors declare no conflict of interest.
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