**4. Discussion**

This study documented the differences in physical fitness between recruits from one LEA who graduated or separated from academy for a variety of reasons. The results provided some support to the study hypotheses. Recruits that graduated were faster in the 75PR and completed more MSFT shuttles when compared to recruits who separated, due to PT failures or injury. Graduating recruits also completed more MSFT shuttles than recruits who separated for personal reasons. However, there were no differences between any of the groups for performance in the push-up, sit-up, VJ, and MBT assessments. These data sugges<sup>t</sup> that, for this agency, there are specific fitness characteristics that could influence and predict whether a recruit graduates academy. Although the stepwise regression data tended to have very low explained variance, it did tend to support the between-group comparison data. It should however be noted that, while the data exhibited a low albeit significant variance, the training stimulus provided during academy occurs across multiple occasions, rather than a single one-off event. As such, there is essentially a cumulative impact of risk. This phenomenon of differential risk accrual over repeated exposures to events occurring during the training program, is discussed in detail by Pope [50]. As will be also be discussed, this could be influenced by the PT practices adopted by the LEA.

The age, height, and body mass of the recruits in this study were typical of that established in the literature [6,20,23,27,28]. Height and body mass were not significantly different between any of the groups. However, the recruits in the SEPAS group were significantly older than the GRAD group, and age was a predictor of inclusion in this group. Age was also a predictor for inclusion in the GRAD group. Recruits in the SEPAS group either failed academic examinations or the requirements needed in law enforcement-specific training scenarios. Time managemen<sup>t</sup> [51], and perceived control of time managemen<sup>t</sup> [52], is important for academic success. Recruits in their late 20's and early 30's may have more outside life influences (e.g., family commitments) that could have influenced the results seen in this study for the SEPAS recruits. Noting the trend toward lower MSFT and slower 75PR results, older officers also tend to have lower levels of physical fitness when compared to their younger counterparts [22,23,31]. This could have influenced the recruits in the SEPAS groups' ability to adequately recover from the stressors of academy, and their subsequent performance in training scenarios. These notions, however, cannot be confirmed by the current research. Nonetheless, outside time commitments and differences in fitness for older recruits could play some role in their ability to complete the academic and scenario training requirements of academy, and could be points to consider for LEA staff.

The SEPFI group performed poorer in the two running assessments (75PR and MSFT) compared to the GRAD group, and the MSFT (albeit with a low explained variance) also predicted inclusion in this group. The 75PR measures high-intensity running and change-of-direction speed [27,28], while the MSFT provides a valid measure of aerobic capacity [53,54]. Running is a heavy focus of PT in the academy period for this LEA [15], so it is understandable that recruits who were superior in running tasks would be in a better position to complete the academy PT requirements and graduate. Furthermore, fitter recruits tend to operate at a lower percentage of their maximal capacity, and as a result can perform certain tasks for longer, fatigue less rapidly, and recover more quickly [55,56]. Shusko et al. [13] also found that police recruits who had a slower 2.4-km run time, which is indicative of lower aerobic fitness, were more likely to separate from academy. Recruits attending academy with poorer levels of fitness, as measured via running tasks, such as the 75PR and MSFT, could be more likely to separate. This could be especially true if a traditional LEA training model, with an emphasis on strength endurance and aerobic fitness, is followed [14,15].

The SEPPR recruits also completed fewer MSFT shuttles than the GRAD group, and the MSFT was a predictor (with a low explained variance) for inclusion in the SEPPR group. A factor that could influence whether a recruit separates for personal reasons is the inappropriate application of PT. As noted, many LEA academies operate via a paramilitary, 'one-size-fits-all' model [5,6,8,14,15], where every recruit is expected to complete the same training regardless of their current fitness or ability. Additionally and as noted, traditional LEA training can often involve a high volume of running [15]. Recruits in the SEPPR group may have found the training adopted by the LEA staff beyond their current physical capacity, which could then have contributed to their voluntary decision to separate. There are certain physiological characteristics that can predispose an individual to be a better runner (e.g., maximal aerobic capacity, lactate threshold, and running economy) [57,58]. While these qualities are trainable [57], there will always be recruits who are better suited to running than others (e.g., they have superior genetics relative to aerobic capacity or running biomechanics) [59,60]. LEA training staff should be wary that they do not lose recruits who are potentially competent LEOs that can perform the relevant job tasks, but are not good distance (e.g., 800 m or longer) runners. Physical fitness can still be improved with lower volumes of running in law enforcement populations, with a concurrent decrease in the risk of injury [5,8]. Given the findings of Trank et al. [61], whereby Naval recruits who ran <40 km (25 miles) where less likely to be injured than those who ran >40 km without negatively affecting physical readiness, future research should investigate moderating the volume and mileage of running during a law enforcement academy, and whether this can influence graduation and separation rates.

It is possible that certain recruits from the SEPPR group resigned for reasons not related to their physical fitness. Further to the PT requirements, a major part of academy is the development of the inherent discipline required in the profession. This can be imposed by the training staff offering very stern commands and directions for expected behaviours [2,3]. Although not measured in this study, there are certain personality types who would be more likely to voluntarily resign for personal reasons. Individuals that ge<sup>t</sup> more emotionally upset, and are more tender-minded, carefree, and impulsive, are more likely to voluntarily terminate employment as a police officer [62]. Given the high psychological stress imposed by training officers during academy [2,3], some recruits may have voluntarily resigned due to this stress, as opposed to that from PT. While this is a possibility, it is important to note that, due to the nature of academy, the psychological and physical stressors imposed by staff will be experienced simultaneously. Further, the recruits in the SEPPR group still did perform worse in the MSFT compared to the GRAD group. If a recruit had personality traits that did not fit well with the law enforcement profession, this could be compounded by poorer aerobic fitness, especially if PT had a high volume of running [15]. Future research should investigate the relationships between reasons for separation and personality traits, and other psychological variables (e.g., self-efficacy, motivation) that may influence academy separation.

Strength endurance tests, such as push-ups and sit-ups, predominate in the fitness assessment of law enforcement populations [1,4,6,13,20,22,24,26,27,30,31,33,35–37]. However, these assessments did not differentiate between recruits who graduated or separated for any reason, or predict any reasons for separation. This is contrary to findings from Shusko et al. [13], who found that recruits performing fewer push-ups tended to separate from LEA academies. The VJ and MBT also did not differentiate or predict recruits who graduated or separated. This contrasts with Orr et al. [9], who found poorer VJ performance was a predictor of injury or illness in Australian police recruits. Injury or illness can lead to academy separation for a recruit [5,8,9], especially if they miss a number of PT sessions [7]. However, the use of body weight calisthenics [14] and the volume of running [15] completed during PT at this academy could have limited the impact upper- or lower-body power may have had on recruit graduation rates. These results emphasize that the PT model adopted by LEA training staff will influence those fitness characteristics that could predispose a recruit to graduating or separating from academy.

There are certain limitations to this study that should be noted. This study incorporated a pre-existing fitness testing battery specific to one LEA. Different agencies may use different assessments (e.g., the 2.4-km run instead of the MSFT) [1,12,20,29–31,63]. This could influence the effects fitness may demonstrate with academy graduation rates. The study results could have also been influenced by the nature of the MSFT, where recruits can voluntarily terminate the test. Training staff could not always guarantee that all recruits reached their maximal aerobic capacity. Nonetheless, this test is an established and valid measure of maximal aerobic capacity [54,64,65], and the data from the recruits in this study was similar to that from previous law enforcement research [27]. Due to the sample size, recruits with PT failures and injuries were grouped together. Even though less fit recruits are more likely to ge<sup>t</sup> injured because the training load could exceed their capacities [47], it is still possible that certain injuries may have been suffered by recruits with higher levels of fitness. No maximal strength tests were included in the battery used in this study, although this is typical of law enforcement research [6,12,20,22–24,26–28,33]. Future research should investigate whether maximal strength could influence whether a recruit graduates or separates from academy. It would have been beneficial to monitor recruit fitness at multiple time points throughout academy. However, timetables can vary across different academy classes, due to the wide variety of skills and procedures that need to be taught to recruits [4–6], and ensuring the requisite staff are available to instruct. Nonetheless, this should be explored in future research.
