# Reliability of Critical Fitness Tests for Police Officers
## 1 Introduction  
Police officers (POs) need adequate fitness profiles to protect society from dangers and safely and efficiently eliminate threats in real time [1]. Motivation for POs to achieve (and maintain) an adequate fitness profile can be obtained by simply taking fitness tests [2]. Police officers in training (cadets and provisional officers) are the population most tested in fitness attributes compared to POs already in operational service.  
In the literature, several fitness tests are being used to assess the fitness attributes of POs [3]. However, according to [PERSON] et al. (2018) [4] and [PERSON] et al. [5], there is great heterogeneity in these populations' fitness assessment protocol components. The authors investigating this topic use very different fitness assessment protocols, and there are no validated fitness protocols for POs [3,5,6].  
According to [PERSON] et al. [3], efforts should be made to use the same fitness assessment protocol (i) to the extent that it allows the results to be used to improve police training plans and (ii) to compare and interpret fitness performances. It is essential to mention that when constructing the fitness assessment protocol for POs, it is crucial to take intoaccount some variables, such as (i) the physical capabilities most used in the literature, (ii) the population to be tested (e.g., candidates, cadets, and career POs), (iii) the time available to carry out assessments, (iv) the equipment and resources to be used, and (v) the specific information to be obtained in each fitness test [7].  
In a previous study to assess the validity and reliability of field-based fitness tests, the horizontal jump, handgrip strength, and 20 m shuttle run tests were selected [8]. The fitness tests protocol was considered (i) valid, safe, and feasible for assessing fitness related to young people's health and (ii) a valuable instrument for monitoring the health of this population [8].  
It is important to note that the construction of an appropriate fitness assessment protocol for POs involves selecting tests that meet the specificities of the population according to the performance of their profession but also ensuring the validity and reliability of the results obtained through the carefully selected tests [7].  
To validate the fitness assessment protocol, it is necessary to carry out the same protocol on two occasions separated by a period of 48 h [9] or a week [10; 11; 12], with most studies adopting an interval of one week between the first (test) and second fitness assessment (retest). In continuation of this testing, the reliability of the results obtained can be assessed using the intraclass correlation coefficient (ICC) and the standard error of the mean (SEM) [9; 12].  
Considering the above, the main objective of this study is to validate a fitness assessment protocol for POs to promote homogeneity in assessing the most critical fitness attributes of POs, also considering sex. Although it is widely accepted and known that men's performance is superior to women's performance in fitness tests, this study also presents a complementary objective to confirm the effect of sex on the fitness performance of POs.  
Following this, we hypothesize that (i) the fitness tests presented in the POs fitness assessment protocol are valid and reliable, and (ii) the fitness profile of male POs is significantly superior to that of female POs.