**1. Introduction**

Law enforcement can be a demanding profession that can place high levels of physical [1] and psychological [2,3] stress on those employed in this vocation. The academy period is used by law enforcement academy (LEA) instructors and tactical strength and conditioning facilitators (TSAC-F) to train recruits to tolerate the physical and psychological challenges of policing, while also teaching the necessary procedures and skills required for the job [4–6]. However, not all recruits will graduate from academy. Recruits may separate (i.e., they do not graduate) for a number of different reasons. These reasons may include personal reasons (e.g., they no longer want to work in law enforcement) [3], physical training (PT) session failures (i.e., they do not complete the requisite number of sessions as mandated by the LEA or state) [7], injury [5,8,9], failure in academics or scenario-based training [10–12]. Recruits that separate create a significant financial burden to an agency [5,13]. Thus, it would be pertinent for agencies to understand whether there are certain physical characteristics that influence whether a recruit graduates or separates from academy. If these characteristics could be effectively measured prior to academy, it may provide useful information for an agency to make more cost-effective decisions as to whether they hire certain individuals.

A major component of academy is PT, which should be tailored towards developing recruits such that they can complete the tasks required in law enforcement. Greater aerobic fitness (as measured via number of shuttles in the 20-m multistage fitness test; MSFT) and strength endurance (e.g., push-up and sit-up repetitions) have been correlated with better performance in job-specific tasks [6,12], which highlights the need for fitness in law enforcement populations. Specific to academy graduation, Shusko et al. [13] found that Massachusetts-based recruits in the USA who completed fewer push-ups in 60 s prior to academy, and had a slower 2.4-km run time, were more likely to separate. Orr et al. [9] found that lower-body power measured via vertical jump (VJ) performance was a predictor of injury or illness in Australian police recruits. Accordingly, physical fitness would likely be a factor influencing a recruit's ability to successfully fulfill the requirements of academy and graduate.

A limitation with PT in the academy setting is that agencies may lack the equipment and space to conduct a variety of training practices (i.e., maximal strength training) which could be useful for a law enforcement officer (LEO) [6]. As a result, many academies tend to focus on strength endurance or callisthenic-type exercises conducted in a circuit training fashion [14], in addition to aerobic-focused training (e.g., long, slow distance or formation runs) [15]. These practices are often conducted within a paramilitary 'one-size-fits-all' training model [5,6,8,14,15]. This style of training may lead to an inappropriate application of training load for certain recruits, which could then increase their risk of injury and/or separation [5,16]. The PT practices adopted by agencies may place greater importance on certain physical qualities for recruits (i.e., if running is a focus, then aerobic fitness may be more important for a recruit). This should also be considered when analyzing the physical fitness qualities influencing academy graduation in LEA recruits.

Academy training is used not just to physically develop recruits, but also to challenge them psychologically in order to assess each recruit's tolerance and demeanor under stress [3]. Berg [2] noted that the stress imposed by the verbal commands of training staff is generally designed to test the mental toughness and resilience of recruits, and find any character flaws that may impede being an effective LEO. As an example, a recruit that displays poor emotional stability in the face of adversity during academy may not be the best candidate to become a LEO, where there are major consequences to poor decisions made in the field under stress. Notably, higher physical and psychological stress has been associated with thoughts about quitting the profession in correctional officers [17]. Recruits with lower levels of fitness may not only find the PT more difficult, but could also experience greater psychological stress within the academy environment. Noting the general adaptation of the biological system to stress proposed by Selye [18], the combination of stress imparted by both physical and psychological stressors may lead to system exhaustion and in turn impact on motivation. Similarly, academic stress can have the same effect when combined with physical stress. As an example, in collegiate athletes, the risk of injury was found to higher during periods of high academic stress when compared to periods of lower academic stress [19]. To the author's knowledge, there has been no analysis of the relationship between physical fitness and voluntary decisions made by recruits to separate from a law enforcement training academy, nor regarding any relationships between physical fitness and academic failure during training academy.

Therefore, the purpose of this retrospective study was to analyze the effects physical fitness may have on academy graduation and reasons for separation in LEA recruits. Although there are limitations with conducting retrospective analyses, this is often a necessity in law enforcement research, due to the constraints and external demands placed on these populations. Furthermore, this is very common in the scientific literature [1,4,6,12,13,20–34]. For this study, the recruits who did not graduate were divided into groups according to whether they: Separated for personal reasons; separated due to PT failures (i.e., poor fitness) or injury; or separated due to academic or scenario failures. It was

hypothesized that recruits who graduated would display superior physical fitness across the different assessments utilized in this study. This would occur regardless of the reason why a recruit may have separated.
