Identifying the Physical Fitness and Health Evaluations for Police Officers: Brief Systematic Review with an Emphasis on the Portuguese Research

Simple Summary Police health and physical fitness are essential for improving quality of life and police skills. This review aims to identify and analyze international and Portuguese studies that have investigated the relationships between various aspects of physical fitness as specified by job descriptions and to understand the health-related requirements of police officers. This will help to select the most used fitness measures and health-related parameters for police officers and improve training curricula for these occupational groups. Abstract This review aims (i) to identify and analyze the most used physical fitness tests for police officers (from international and Portuguese studies) and (ii) to understand the health-related physical fitness requirements according to the job descriptions of police officers. A total of 29 studies were included. Eighteen were from around the world and eleven were related to Portuguese police officers. All studies showed acceptable methodological quality in the assessment of physical fitness, and the most used fitness components were muscular strength, endurance, power, aerobic and anaerobic capacity, flexibility, and agility. For the analysis of health parameters, they are insufficient at the international level, while at the Portuguese level we have an acceptable sample. We try to analyze the relationship between physical fitness and health, but the studies conducted so far are insufficient. This review provides summary information (i) to help select the most used fitness measures and health-related parameters for police officers, and (ii) that will serve as a starting point for evaluating the relationship between the health and physical fitness of police officers.


Introduction
Law enforcement can be a physically demanding, dangerous, and stressful profession that has health implications. The health and physical fitness of police officers is essential to their performing their duties well [1,2].
Police officers must undergo various physical tasks that include carrying external loads, such as running, restraining offenders, self-defense, and manual handling tasks [3]. They also have social and psychological obligations (e.g., the daily pace of work, job responsibilities, and stress/risk situations). It appears that the physically demanding jobs require high levels of cardiovascular fitness as well as muscular strength and endurance [3][4][5].
The field of public safety has high physical fitness and health requirements for entry into police academies. While recruits learn the physical challenges of the profession while being taught the necessary procedures, skills, and the values and behaviors expected of a police officer, these health-related attributes are only assessed for entry and rarely thereafter [6].
According to the literature, a police officer's physical fitness tends to decline over time. Previous studies suggest that improving traditional health-related components of physical fitness (i.e., body composition, cardiorespiratory fitness, muscular strength, endurance, and flexibility) is essential for improving quality of life and policing skills [7,8]. However, the risk of developing health problems increases with overall decline in physical activity and associated decline in physical fitness. In fact, low levels of muscle fitness and physical endurance as well as overweight and obesity have been shown to be risk factors for police officer health and to lead to lower productivity levels and sick leave [9], resulting in additional costs to the employer. A high prevalence of cardiovascular risk factors has been found among police officers, including metabolic syndrome, hypertension, hyperlipidemia, smoking, and physical inactivity [2].
Studies on the physical activity, physical fitness, and health of Portuguese police officers are scarce. Therefore, this review aims (i) to identify and analyze the most used physical fitness tests for police officers (from international and Portuguese studies) and (ii) to understand the health-related physical fitness requirements according to the job descriptions of police officers.

Experimental Approach to the Problem
A systematic review was conducted to identify the physical fitness tests used on police officers and to describe the fitness levels of this population. This systematic review followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model [10]. This study is exempt from ethical approval because the authors collected and synthesized data from previous studies in which informed consent had already been obtained by the study investigators. Therefore, this study was not approved by an institutional review board.

Search Strategy
To identify and obtain relevant original research for the literature review, key literature databases were systematically searched using specific keywords relevant to the topic. The databases searched included PubMed (https://pubmed.ncbi.nlm.nih.gov/?term=police+ officer+AND+Physical+Fitness+AND+Health&sort=date, accessed on 28 September 2021), ScienceDirect (https://www.sciencedirect.com/search?qs=Police%20AND%20Fitness% 20test%20AND%20health, accessed on 28 September 2021), and ISCPSI (Higher Institute of Police Sciences and Internal Security) common repositories (https://comum.rcaap.pt/ handle/10400.26/6300, accessed on 28 September 2021). These databases were selected because they contain a large number of high-quality, peer-reviewed articles and represent journals relevant to the topic of the study. The final search terms and applied filters for the databases searched are summarized in Table 1.
To improve the relevance of search results, filters that reflected study eligibility criteria were applied in each database when available. In the ISCPSI database, where these filters were not available or were only partially available, eligibility criteria for studies were applied manually by screening study titles and abstracts. The eligibility criteria were then applied to the full text of identified articles that were not excluded during the screening of titles and abstracts to make a final selection of eligible articles for this review. The results of the search, screening, and selection processes were documented in a PRISMA flow diagram ( Figure 1) [10]. The inclusion criteria were defined to include individuals from law enforcement, to measure physical fitness, and to measure health. The exclusion criteria were: studies older than 15 years, studies examining only body composition, studies addressing instrument development, studies addressing only weight bearing, studies addressing only screening instruments, validity studies, and reliability studies. Duplicates were removed after all studies were collected.

Critical Appraisal
To assess the methodological quality of the study, the CASP consists of a checklist of ten questions. Each question can be answered "yes," "can not say," or "no." Questions six and seven are short answers that we left blank due to their subjectivity (Critical Appraisal Skills & Programmes, 2018). Methodological quality was also assessed individually by two authors to avoid bias.

Data Extraction
After critically analyzing all articles, we extracted the following information: authors and year of publication; study population; measures (physical fitness tests); measures (health parameters or questionnaires); main results; general conclusions. All of the information is presented in Tables 2-4 [2,7,.

Critical Appraisal
To assess the methodological quality of the study, the CASP consists of a checklist of ten questions. Each question can be answered "yes," "can not say," or "no." Questions six and seven are short answers that we left blank due to their subjectivity (Critical Appraisal Skills & Programmes, 2018). Methodological quality was also assessed individually by two authors to avoid bias.

Data Extraction
After critically analyzing all articles, we extracted the following information: authors and year of publication; study population; measures (physical fitness tests); measures (health parameters or questionnaires); main results; general conclusions. All of the information is presented in Tables 2-4 [2,7,.

CS anthropometry SK measurements
An increase in body fat percentage is associated with a decrease in performance. Estimated lean body mass was significantly and positively correlated with push-ups, 1RM bench press, and vertical jump, whereas an increase in estimated fat mass was significantly associated with decreased performance in sit-ups, vertical jump, 1.5-mile run, and estimated VO 2max . Reducing body fat mass while improving metabolic fitness and muscular endurance should be the goal of conditioning training to improve performance in sit-ups and running times (over short or longer distances). Increasing lean body mass and decreasing body fat mass can both positively affect vertical jump performance. Percent body fat mass was linearly and positively related to time of 2.4 km run and linearly and inversely related to number of push-ups, sit-ups, and sit-and-reach in males, and similar associations were observed in females, except for sit-and-reach. Percent body fat mass was inversely associated with fitness level in men and female. Officers with a higher percentage of body fat mass had lower cardiorespiratory capacity, lower dynamic strength, and lower flexibility. Male cadets had significantly lower body fat mass than male officers, which can be explained by age differences between these groups. Male cadets were more aerobically fit and had greater muscular endurance than male officers, regardless of age.
Male cadets also had greater anaerobic fitness than male officers, although age differences only partially explained this difference. Female cadets exhibited higher upper body strength and muscular endurance than female officers, regardless of age. Individualized training approaches that target the observed increase in body fat mass associated with aging would be beneficial for police officers, whether they are cadets or on-duty officers.  Age, gender, vertical jump height, leg power, number of pull-ups and push-ups, kilograms pulled, and VO 2max were significantly related to musculoskeletal injury incidence.
The results suggest an interaction between gender and VO 2max , such that the effect of VO 2max on injury risk cannot be understood without accounting for gender. The relationship between occupation-specific fitness test performance and work-related injuries will provide new insights for prevention strategies.  There is a need for health-promoting measures and concepts, such as company sports or nutrition courses, to counteract cardiovascular and metabolic risk factors.
BIA, bioelectrical impedance analysis; BMI, body mass index; CS anthropometry, classical anthropometry; DXA, dual-energy X-ray absorptiometry; CMJ, countermovement jump; HR, heart rate; IPAQ-S, International Physical Activity Questionnaire-Short Form; PSDQ-S, Physical Self-Description Questionnaire-Short Form; SK measurements, skinfold thickness measurements; SJ, squat jump; VO 2max , aerobic capacity. Mean scores were also lower compared with elite police officers in an older age group in Portugal and compared with regular police officers of similar age from Portugal and from the United States. Participants reported higher average values for pull-ups, sit-ups, and push-ups than elite police officers in Portugal who were in an older age group. For VO 2max prediction, participants reported lower average values than elite Portuguese police officers who were in an older group and within the interval average range identified in a recent systematic review. The participants' mean systolic blood pressure values were categorized as "pre-hypertensive" and diastolic blood pressure as "normal". The Portuguese recruits were found to be extremely fit and had robust physical fitness and anthropometric profiles, as well as good metabolic indicators. In addition, the study would contribute to the development and implementation of regular exercise and training programs aimed at maintaining high levels of physical fitness throughout the career and lifespan of police officers, thus optimizing their deployment, with a potential positive impact on overall health.
BIA, bioelectrical impedance analysis; CS anthropometry, classical anthropometry; DXA, dual-energy X-ray absorptiometry; VO 2max , aerobic capacity.   There was also a strong negative correlation between fitness variables and time spent on the circuit, i.e., the higher the fitness level, the shorter the time spent performing the circuit for on-duty tasks. The pull-ups, agility test performance, and right-handgrip values explained the variation in performance. The use of personal protective equipment significantly degrades the performance of elite police officers and interferes with their police work. Female performance was lower than male performance in physical tests. Throughout the course, physical condition was maintained/improved, except for aerobic capacity in males. As age group increased, performance in physical fitness tests tended to decrease for both genders (except for handgrip and back-leg-chest strength). The police academy course managed to maintain the physical fitness of the cadets. The 20-29 age group is the one with the best physical fitness for both genders. Cadets older than 29 show the greatest drop-off in performance in physical fitness tests for both genders.

Fitness Measures
The most commonly used fitness components were muscle strength, endurance and power, aerobic and anaerobic capacity, and some tests of agility and flexibility.
The results of this study have important implications for the selection of the most commonly used fitness measures for police officers and for the improvement of training plans for police officers, which we have summarized in a synoptic table (Table 5). Aerobic capacity [20,21] Agility t-test (in 1 article) Agility [20]

Discussion
All studies showed acceptable methodological quality in the assessment of physical fitness. The analysis of health parameters is insufficient at the international level, while at the Portuguese level we have an acceptable sample for police health. However, if we try to analyze the relationship between physical fitness and health, the studies conducted so far are insufficient, though we will return to this point later.
We believe it is important to standardize the scores for the different physical abilities, using our synoptic table to achieve consistency in the assessment parameters for police function.
Regarding health status in terms of physical fitness, a general decline in certain physical attributes between genders has been observed with age [26]. Aerobic capacity emphasizes the need for physical training in order not to compromise performance and to mitigate the effects of increasing age [17,22]. Several studies have shown that the increase in body fat percentage is associated with a decrease in performance and physical fitness [24,27,28]. An increase in lean body mass and a decrease in body fat percentage can positively affect vertical jump performance [24]. Higher body fat percentage resulted in lower cardiorespiratory capacity, lower dynamic strength, and lower flexibility [27]. Moreover, it was proved that improving metabolic fitness and muscular endurance should be the goal of conditioning to improve sit-up performance and running times [23,24]. Agility, aerobic capacity, push-ups, and sit-ups were significantly correlated with police officer tasks [22].
The development of health-related fitness standards and associated health and fitness strategies will help improve officer health and fitness. A strong correlation was found between the morphological, cardiorespiratory, and neuromuscular components of healthrelated physical fitness [29]. Physical fitness (including anthropometric measures) and health measures should be used together to guide conditioning interventions to improve police performance [12,13,19,22,24,35].
Analysis of these studies with police officers confirms that physical fitness is extremely important for the performance of operational tasks and has a direct influence on health status. Body composition showed a direct influence on physical fitness and cardiovascular risk. In addition, decreased cardiorespiratory fitness was associated with an increase in age-related cardiovascular and metabolic risk [13][14][15]21,22,28,30,34,37]. However, there is a need to implement health-promotion interventions to address cardiovascular and metabolic risk factors [37]. Several studies have found a significant association between age and decline in physical fitness [12,13,[15][16][17]21,22,26]. It is critical that police officers maintain appropriate levels of physical fitness as they age [22,26].
However, a limitation of this review was that it was not possible to screen studies that reported on physical fitness and its relationship with health parameters. Few clinical parameters were evaluated to critically analyze this risk relationship. Furthermore, the great variety of physical fitness assessments studied can also be considered a limitation, as the diversity of tests makes it difficult to standardize the protocol for fitness assessment. Another limitation was the inclusion of studies with cadets/recruits and cadets who are not yet police officers.

Conclusions
The police profession involves special challenges to the health, physical, and psychological statuses of police officers. The risks of performing police work have numerous, complex, and long-lasting consequences that affect not only the quality of everyday life of police officers, but also the efficiency of the measures and activities undertaken. Therefore, it is necessary to maintain physical condition at an optimal level over a long period of time, monitor changes in the health status of police officers, and point out in a timely manner the positive and negative implications of irresponsible attitudes towards these issues by police officers and police management.
In fact, our research shows that a variety of physical fitness tests exist to assess and predict police officer performance. More and more tests are being used to assess various physical abilities, such as muscular strength and aerobic capacity, but agility and flexibility are still poorly assessed. However, health-related tests are rarely used as a complementary method to diagnose physical and health conditions, even though it is known that there is a direct relationship between the two.
For such a research endeavor, the existing work is a good starting point; the literature referred to also indicates possible directions for research engagement (e.g., researching correlations between regular physical activity, efficiency of police work, and monitoring changes in police health status), and the contextual framework provides an opportunity to identify and use key determinants that shape the health quality of police officers. Accordingly, efforts should be made to evaluate the same protocol of physical fitness tests and include health parameters and to use the results obtained to improve training plans for this occupational group.