Styles of Coping with Stress as a Factor Inﬂuencing Professional Burnout among Professional Ofﬁcers of the Polish Army in the Context of Their Age

: The subject of this article is the issue of coping with stress in the context of the level of professional burnout among professional soldiers at the ofﬁcer rank and the identiﬁcation of the relationship between occupational burnout and the preferences of the style of coping with stress and the age of the respondents. The study aims to answer the following questions: how does occupational burnout (its individual dimensions according to the concept underlying the construction of a research tool) depend on the style of coping with stress, and whether and how the level of occupational burnout changes depending on the age of soldiers? The study consists of two parts: a theoretical one, in which the issues are presented in relation to the literature on the subject, and an empirical section, presenting the results of research in which 200 soldiers of the Polish Army with the ofﬁcer rank participated. The research was carried out using questionnaires that met the requirements of psychometric correctness (Coping Inventory for Stressful Situations—CISS and Link Burnout Questionnaire—LBQ). As a result of the research, it turned out that the level of occupational burnout depends on the choice of the style of coping with stress (a higher level of burnout is favored by the preference for an emotional coping strategy), while the style of coping with stress and the level of occupational burnout among professional soldiers with the rank of ofﬁcer changes with age. The presented research, mainly due to the speciﬁcs of the research group, was not undertaken and described in the literature on the subject.


Introduction
The issues of the styles of coping with stress of professional soldiers' burnout in the context of age are part of the idea of sustainable development. The idea of sustainable development in theoretical and practical terms has been developing intensively for over 30 years. Over the last fifteen years, its development can be clearly observed in many different scientific disciplines, i.e., environmental science, technical sciences, social sciences, economics, management, sociology, humanities, psychology, pedagogy, and health sciences. This is indicated by numerous literature studies, i.e., Jackson [1] and Van der Waal and colleagues [2], who regard sustainable development as a system designed to maximize social and environmental benefits instead of prioritizing economic growth. The 2030 Agenda adopted by the United Nations in September 2015 as a global plan for sustainable development refers not only to the challenges related to climate change and degradation of the natural environment but also aims to counteract all (overt and hidden) forms of social exclusion, social inequality, e.g., discrimination in the labor market [3] and to promote appropriate attitudes in the field of social education, both narrowly and broadly understood. An example of this approach is also a holistic, new vision of the world, taking into account the humanistic paradigm and human well-being in introducing any changes not only in the surrounding environment but in the process of education in the area of work, using social media [4]. A continuation of these considerations is the need to manage diversity and to promote appropriate patterns of behavior, good practices supporting the functioning of specific groups of employees in the workplace [5,6]. In the literature on the subject, there is a lot of evidence indicating the perception of greater age advancement, combined with longer work experience, as a factor limiting the efficiency of professional functioning, a synonym of a negatively treated work routine [7,8]. At the same time, there are few studies focusing on promoting a different, stereotype-breaking, interdisciplinary approach (from the perspective of sociology and environmental psychology) to diversity management in relation to selected professional groups [9]. For this reason, it seems advisable to undertake further research to verify the findings to date and to provide up-todate, empirical evidence which constitutes real dependencies and creates a reliable picture of reality. The interdisciplinary and humanistic approach to the issues of sustainable development results in both the development of the idea itself (cognitive aspect) and its implementation into practice (application aspect), undertaking further research, both qualitative and quantitative.
Professional soldiers (especially officers) are a group that is particularly exposed to stress. Soldiers must cope with stressors during both military operations and training if they are to accomplish their missions successfully and stay mentally stable [10]. In addition to this, in the military, there are certain categories of personnel among whom the probability of burnout increases [11]. So, soldiers do dangerous and stressful work, and military personnel have an elevated risk of suffering from stress-related disorders following military deployment [12]. The risks of developing other psychological disorders such as depression, anxiety, and alcohol abuse are also high [13]. The intense experience of stress that generates occupational burnout almost always causes physiological reactions that are unfavorable for the human body [14].
One of the factors specific to the work of a soldier is the fact that it is performed with a much more rigorous discipline than in civilian professions. Soldiers belong to this social group in which the goal, norms, and orders are imposed from above. Some people identify fully with the goals and forms of functioning, others fall into conflict. A closed group of people, not always having identical attitudes towards various aspects of the environment, has a limited chance of reacting to negative emotions. A soldier of the professional service functions in an institution where the dominant management style is the directive style. The results of our own research on another uniformed group revealed that for job satisfaction, the most important thing in the organizational climate is the relationship with the immediate superior [15], as well as other factors, e.g., time pressure, working conditions, personality factors, types of stressors [16]. It can be expected that in this situation the choice of a coping strategy may be a factor limiting or increasing occupational burnout, resulting in lower motivation to work and numerous health issues. The subject of this article is therefore the issue of the relationship between occupational burnout, the style of coping with stress, and the development of occupational burnout in relation to the age of soldiers at the rank of Polish Army officer.
Analyzing the current theoretical considerations and research results, it can be expected that the choice of the style of coping with stress moderates the level of occupational burnout understood as its consequence [17], in particular, those related to the workplace, contribute to the occurrence of occupational burnout [18][19][20]. At the same time, it should be stated that there is no complete agreement in the literature regarding the role of age in experiencing stress and occupational burnout. Taking into account the above circumstances, i.e., the specificity of stress loading in the officer's profession, the relationship between the style of coping with stress and occupational burnout and age, the aim of the article is the identification and verification of the relationship between burnout, the style of coping with stress and the development of occupational burnout in relations to the age of soldiers at the rank of Polish Army officer.

The Stress Response in the Transactional and Resource Concept of Stress
Traditional models of stress that treat stressors as causing emotional tension treat job characteristics as stressors, while stress is understood as a physiological or psychological response to stressors [21]. Therefore, it is assumed that stressors (e.g., time pressure, sense of threat) are the causes of the responses to workload. Expanding this perspective, the transactional stress model [22] assumes that the stressor-experience, stress relationship are determined by two mutually dependent processes: (1) evaluation; and (2) stress-coping activities [23].
Assessment refers to an evaluation process by which people identify their capabilities against the threatening features of the work environment to determine if these features enable them to overcome the stressor. If the work environment is judged to be burdening or exceeding a person's resources, coping strategies are triggered to protect their well-being. These coping strategies include attempts to change the person-environment relationship (i.e., coping with problems) and/or attempts to regulate the experience of emotions, i.e., coping with them [22,24]. Consequently, people experiencing tension, if they assess the features of the environment, and in particular the work environment as a threat to their well-being, gain the conviction that they cannot do much in terms of changing the aforementioned relations between the environment through their own activity, as well as the awareness that they cannot regulate self-resulting from the problems of negative emotions. Thus, the transactional model of stress maintains that difficult-to-routine work experiences are not only a function of objective stressors, but are determined by a subjective evaluation of these stressors and associated coping strategies.
As a result, responses to stress can vary. According to Endler and Parker [25], strategies for coping with stress that a person undertakes are the result of an interaction between the features of the situation and the reaction style characteristic of a given individual. The style of coping with stress is understood as a way of behaving in various stressful situations, typical of a given person. Thus, the choice of a coping strategy (style) depends on many factors, e.g., the person's personality, experience in coping with stress, the type of stressor that caused the state of emotional tension.
According to the authors of the concept [26], the goal of coping with stress does not have to be realized by the individual, and the assessment of the situation does not have to be realistic. Sometimes it happens automatically. This enables the use of specific defense mechanisms as forms of coping with an emotionally burdensome situation, despite the fact that they are based on an unconscious distortion of reality, but at the same time, it would be difficult to argue that they play an important adaptive role in a stressful situation.
The choice of a specific strategy is conditioned by a number of factors both on the part of the individual and his environment.
Stevan Hobfoll is the author of the concept of stress known as Conservation of Resources Theory (COR). For the author, the concept of resources is particularly important and of central importance to the problem of stress. Their acquisition, maintenance, and protection against loss is an extremely important competency of an individual. Hobfoll's resources include "objects, conditions, personality traits, energy that are valued and needed directly or indirectly for survival or are used to gain new resources" [28]. Continuing his deliberations, the author divides resources related to coping with stress, which are closely related to the survival of an individual, and are also interdependent into the following four groups: • material resources, • state resources (health, family, good job, and others), • subjective-personal resources (psychological factors, personality traits), • energy resources.
The possibility of using the abovementioned resources determines the reaction in a stressful situation and the choice of a specific coping strategy.
The already quoted Hobfoll emphasizes that personal resources related to psychological traits are shaped in the course of early developmental experiences in healthy relationships with parents, based on love, respect, and safety, as well as in the peer group during early education and subsequent relationships in the workplace. State resources play a special role. Access to other resources depends on them and they are related to the category of social roles. Some of these resources must be earned by the individual during his or her life, the rest is the result of inheritance. Energy resources can be exchanged for other categories of resources, but, according to the author, they are most valuable before replacement.
The author has compiled his own list of 74 resources that he has included in the COR theory [28]. In the Theory of Resource Behavior, "psychological stress is defined as a reaction to the environment in which there is a threat of loss of resources or the loss of resources has already occurred or the expected profit has not been achieved, and resources have been unnecessarily invested-which means a loss" [29]. According to Hobfoll, when people experience stress, they use the available resources to adapt successfully, which the author describes as investing resources. The effectiveness of coping with stress depends on their availability. Therefore, it is necessary to invest resources to prevent their loss, compensate for losses, and gain new resources [30].
In the case of resource management, this model talks about two cycles: profit and loss. According to the author, they run in two spirals, called the profit and loss spiral. Losses are very acute, because people who do not have much to invest, because as a result of continuous operation under pressure, were unable to make up for the losses, they only try to protect their remaining, small resources. This often leads to passive behavior and to the chronic effects of stress, resulting in burnout. Moreover, scarcity of resources increases the risk of loss as well as entails further losses of resources. This shows the importance of conducting research on people particularly exposed to their loss, e.g., public service employees, including people at risk of professional burnout and loss of health.

Burnout as a Consequence of Stress
The subject of this part of the study is the issue of burnout, which is a specific phenomenon and concerns people professionally involved, who often see a sense of the meaning of life in their work. At the same time, these people experience constant emotional tension in connection with their work, leading to numerous and very unfavorable consequences for us all. This phenomenon occurs when stress is part of the professional role. Burnout always occurs in the area and context of specific social relations, so the awareness of the occurrence of circumstances that are particularly favorable to it in the organization is a particularly important problem. The abovementioned over-involvement is treated as an intermediary variable that influences the health of a person functioning in a specific work environment.
Burnout is a well-documented psychological response to chronic occupational stressors. Burnout has three components, emotional exhaustion, cynicism, and a sense of personal achievement; emotional exhaustion and cynicism are considered the basic elements of occupational burnout [31,32]. Previous studies focused on analyses relating to the helping professions. Research has shown that a high level of occupational burnout is associated with high workload and a mismatch between professional requirements and the personal abilities of an individual, job dissatisfaction, absenteeism, and high turnover in the workplace.
However, Schaufeli and Buunk [33] note that the relationship between burnout and job rotation is often weak, suggesting that many burned-out workers remain in their jobs, often resulting in negative consequences both for themselves and for the organization, then only thoughtful leadership behavior can protect employees from burnout.
Burnout refers to the psychological response to chronic stress at work [34]. The estimated incidence of severe burnout ranged from two to thirteen percent in representative working populations [35]. The resulting costs (in psychological, social, and economic terms) are mainly the result of linking burnout with poor health and work capacity. Prospective studies have shown that burnout predisposes workers to coronary heart disease, type 2 diabetes, common infections, musculoskeletal pain, and symptoms of depression [36,37]. In addition, burnout can increase the risk of serious injury, sickness absenteeism, invalidity pension, and even premature death [38].
According to the most common conceptualization, burnout decreases professional effectiveness [39]. The concept of occupational burnout is derived from social service workers, among whom contacts with other people constitute the majority of their tasks and can become a source of stress [40]. In the human services sector, the symptoms of burnout relate to interactions with clients (emotional exhaustion, disappointment, the feeling of diminished personal achievement) [41].
Generally, predisposing job characteristics include high workload, role conflict and ambiguity, low predictability, lack of social support, and experienced injustice. The aforementioned characteristics of the trait may also increase the susceptibility to burnout itself [42].
Research has shown that a low sense of coherence, alexithymia, neuroticism, low extraversion, agreeableness, and conscientiousness are associated with higher chances of burnout. In addition, environmental factors, in particular those related to the workplace, contribute to the occurrence of occupational burnout [43].
Professions of social services are considered to be highly burdensome, and those in militarized fields, where work consists in constant intensive contact with other people, engaging in their social, psychological, and physical problems. This problem was first noticed in health care and social workers who deal with people in difficult life situations on a daily basis. Performing these professions is mentally burdensome, and emotional exhaustion becomes a very common reaction to the loads encountered at work. So, in such situations, stress is part of the professional role.
Burnout is an individual experience of stress set in the context of complex social relationships. It appears in professions where close, engaged interaction with another person is the essence of professional activity and determines success in a given profession and development. The costs of this close interaction, confrontation with negative emotions, suffering, and a chronic condition may arise when such persons (professional soldier, doctor, teacher, nurse, etc.) are unable to cope with professional burdens, experienced failures, and lack of success. They suffer from increasing fatigue and emotional exhaustion. Burnout is the result of chronic mental exhaustion, a sense of being used by others, and a lack of a deeper sense of action. Thus, significant factors influencing the level of occupational burnout are both the stressors of working conditions and the properties of the individual characteristics of the individual.

Age and Specificity of Stressors
An analysis of the literature on the subject shows that there is evidence that the impact of stress at work differs depending on the period or stage of life in which it occurs [43][44][45][46]. On the other hand, there are studies that do not fully support this theorem, so research conducted by Gotz et al. [47] showed that the older employees who participated in the study experienced more stress than their younger colleagues but it should be emphasized that this relationship did not receive the criterion of statistical significance. Some theories described in the literature on the subject take into account age differences in terms of both the quantity and quality of work-related stressors, with most of them making predictions in favor of older workers. The hypothesis about the increase in job satisfaction with age [48,49], presented and verified initially to explain that on average older employees shoved a higher level of job satisfaction than their younger coworkers [50], led to the claim that career development usually depends on age. This means that the longer employees are involved in their professional work, the more willing and better they are to do it. Therefore, it could be argued that by working longer in certain work environments, building strategies for coping with stress, employees with longer seniority face fewer work-related stressors.
At the same time, considerations of other authors [19] regarding the age of the respondents with age suggest that older workers may experience increased levels of work-related stressors. One such condition may be discrimination against older workers by their younger colleagues or by organizational policies. Age-related stereotypes are commonly found in professional work [51,52] and often contain negative assumptions about the capabilities and competencies of employees with longer experience.
Therefore, it can be concluded that as a result of the conducted research, there are no clear findings allowing us to draw unambiguous conclusions regarding this impact at particular stages of life, which motivated the authors of this article to further penetrate the issues raised.

The Specificity of Stress Among Professional Soldiers
In the army, discipline determines the effectiveness of action. It can be achieved in various ways, either through the method of obedience based on the authority of the commander or through conscious discipline, and is voluntarily submitted to it, internationalizing the principles of the entire formation. Regardless of the way the discipline is shaped, two crucial elements are always key to strengthen it: punishment and reward [53]. At the same time, military discipline, combined with many other factors, such as psychological overload, exposure to traumatic stressors, etc., can be a source of occupational stress. Discipline in this profession comes down to a significant restriction of the freedom of action. Coercion causes psychological stress according to the model of requirements-control-support. Due to the requirements of discipline, control over one's own action plans and intentions is limited to the extent specified by regulations, statutes, and orders. Another specificity of professional military service is an extensive hierarchy. The army is a formal group with a hierarchical order, with an extensive system of positions, powers, and ranks. The functional relationship between the supervisor and the subordinate may force a style of action that is not entirely comfortable for the individual and as a consequence of action results in work stress. The hierarchy also determines the structure of the organization as a system. It is characteristic for military systems that value, e.g., honor, bravery, and courage allow some soldiers to cope better with military stress [54]. On the other hand, positive experiences regarding coping with earlier difficulties and their appropriate narrative, which is conducive to maintaining relatively high self-esteem, are not without significance [51]. From the point of view of the transactional theory of stress, it is particularly important to have positive experiences in coping with stress and difficult situations in one's life [29,55].
In the literature on the subject, there are numerous data showing that the strong stress load, characterizing the professional involvement of professional soldiers is one of the most important causes of occupational burnout and, consequently, numerous psychosomatic diseases diagnosed in this group of people, at various stages of life [56,57]. So far, approximately forty potential work-related stressors have been identified. The five most common categories of sources of stress are activities that make up the work process and the way it is organized; the way the employee is positioned in the production process, including the type and scope of professional responsibility; the employee's professional career; interpersonal relations, and organizational climate, in particular the style of team management. Military service is a type of professional commitment that is particularly exposed to stress-ful situations. The main reasons for the occupational stress of soldiers include physical and organizational working conditions (pace, extended working hours, excess tasks, lack of equipment); professional role (ambiguity of goals, excessive or contradictory requirements, difficulty in reconciling the professional role and family responsibilities); responsibility for subordinates; interpersonal relations (low level of delegation of powers, insufficient support from superiors); service climate (limitation of initiatives, low level of participation in decision-making, inadequate assessment of official activities); conditions for personal development and job security (too fast or too slow professional development, uncertainty of the future, lack of development prospects) [16].
Most often, these factors do not appear individually but constitute a complex of causes of varying intensity and specific, variable dynamics of their impact. In turn, the research conducted by Gąsiorowska shows that both in the group of non-commissioned officers and officers, the most common factors causing stress are: fear of losing a position and job; responsibility for subordinates; excess of tasks, and constant availability [58].
Another author, analyzing the sources of stress on vessels, distinguished a high concentration of people on the ship, excessive monotony of performed tasks, tension and inability to discharge it, informal contacts and inappropriate interpersonal relations, disturbance of the circadian rhythm, and bad quality of the equipment [59].
The dissimilarity of these factors results from the specificity of the environment, according to the assumptions of the concept of stress, it is a factor disturbing the balance and significantly hindering adaptation to the environment.

Research Method
The following research statements were formulated in the research procedure:

1.
What are the relationships between the preferred style of coping with stress in professional soldiers with the rank of Polish Army officer, and the individual dimensions of professional burnout (professional exhaustion, lack of commitment to customer relations, sense of professional effectiveness, disappointment) and the general level of burnout? 2.
How is the professional burnout of Polish Army officers related to age? The formulated problems enabled the adoption of the following research hypotheses: • H.1. There is a relationship between the style of coping with stress and occupational exhaustion. • H.2. There is a relationship between the style of coping with stress and the feeling of disengagement in relationships with clients. • H.3. There is a relationship between the style of coping with stress and the feeling of professional ineffectiveness. • H.4. There is a relationship between the style of coping with stress and disappointment. • H.5. There is a correlation between the style of coping with stress and the overall level of burnout. • H.6. Occupational burnout decreases with the age of the surveyed officers.

Research Tools Used in the Research Procedure
The following research tools were used in the research procedure: Coping Inventory for Stressful Situations (CISS) and Link Burnout Questionnaire (LBQ).

Coping Inventory for Stressful Situations (CISS)
Comparing the results obtained in the individual scales of the CISS questionnaire makes it possible to find and define the dominant way of coping with stress [25]. This allows you to diagnose whether a specific person is constructively coping with stress, or, by presenting inadequate behavior, increasing its level.

CISS investigates which of the four styles distinguished by Lazarus and Folkman the respondent uses [22]:
• Task-focused style-SSZ • Emotion-focused style-SSE • Avoidance-focused style-SSU engaging in alternative activities-ACZ looking for social contacts-PKT The first scale (SSZ) determines the style of coping with stress focused on the task. People with high scores on this scale in stressful situations tend to make efforts to solve the problem through cognitive transformation leading to self-calming or trying to change the situation. The main focus is on the task or planning to solve the problem.
The second scale (SSE) examines an emotional-focused style of coping with stress. This style occurs in people who, in stressful situations, focus on themselves, on their own emotional experiences, such as anger, guilt, tension. These people sometimes also tend to wishful thinking and fantasizing. The purpose of such activities is to reduce the emotional tension associated with a stressful situation. Occasionally, however, such actions can lead to a greater sense of stress and make people tense or depressed.
The third (SSU), defines the style of coping focused on avoidance. People who choose this style in stressful situations tend to avoid thinking, experiencing, and experiencing these situations.
Each of the scales listed consists of 16 items and allows you to obtain from 16 to 80 points [60].
The CISS questionnaire consists of 48 items. The respondent determines on a 5-point scale the frequency with which he/she takes a given action in difficult and stressful situations.

Link Burnout Questionnaire (LBQ)
This questionnaire is a Polish adaptation of the Italian questionnaire, the Link Burnout Questionnaire (LBQ) [41,61], it is intended for the study of occupational burnout and most often used among people working in professions related to providing help or influencing other people, in the so-called social which require entering into direct relationships with other people [62].
The LBQ questionnaire allows the assessment of the following four aspects of burnout [ Psychophysical exhaustion. This is the dimension of one's own psychophysical resources. When constructing this dimension, Christina Maslach's proposal was taken into account to consider this construct not only in terms of fatigue but also the energy and strength available to drive in a work situation. Thus, the items of the questionnaire refer to both negative symptoms (feeling of tension, being under pressure) and also positive symptoms (feeling of being active, full of energy) [41]. Thus, psychophysical exhaustion is a dimension related to the assessment of one's own psychophysical resources, described by exhaustion, fatigue, a sense of tension and being under pressure, and the other, by the feeling of being active and full of energy [62].
The lack of commitment to customer relationships. The term "disengagement" describes the quality of the relationship between employee and customer. In the most serious cases, the employee becomes incapable of paying attention to the specific needs of the interlocutor, his manner of revealing and expressing his needs, the interlocutor (client) becomes an impersonal entity whose requests are met with the least possible effort [41]. Excessive distance on the part of the employee makes the relations between interlocutors inappropriate from the point of view of satisfying other people's needs. On the other hand, an active and committed attitude towards the client makes a given relationship satisfactory and provides full respect for the individual characteristics of each client. This construct is therefore a continuum from engagement in relation to distance [41].
Feeling of professional ineffectiveness. The feeling of professional ineffectiveness is a dimension related to the assessment of one's own professional competencies. One end is characterized by a sense of effectiveness at work, effectiveness in achieving professional goals, and the other end, a sense of ineffectiveness and lack of results at work [62]. The main aspect of perceiving oneself as an effective person, able to achieve goals in one's work is the psychological well-being of the individual, as this dimension influences self-esteem and future commitment to the profession [41].
Disappointment. The idea of including this construct in the definition of burnout is related to reflection on experience. Disappointment takes the form of a loss of enthusiasm for everyday tasks that cease to enrich the meaning and value of everyday life. Burnout is the end state of a long process of disappointment [41]. The manifestations of disappointment include, on the one hand, the expectations of professional activity, and the possibility of realizing through work the values and ideals that are believed in, on the other hand-these are the loss of passion and enthusiasm that was present in the initial expectations [41].

Description of the Research Sample
Professional soldiers with the rank of an officer from eight randomly selected military units in Poland participated in the research. The condition for conducting the research was the consent of the commander of the unit, although direct participation in the research was voluntary.
The gender distribution (Table 1) of the Polish Army officers' professional group shows that men constitute the vast majority of the sample. Most of the officers of the Polish Army are between 30 and 39 years of age, which made up more than 50% of the respondents. The average age of the Polish Army officers is 35 years.

Findings
The obtained data showed both the existence of differentiation in the results of the questionnaire for the study of the coping style and the individual dimensions of burnout (Table 2).

The Relationship between the Style of Coping With Stress and Occupational Exhaustion
The conducted analysis (Table 3) of the multiple regression model confirmed a statistically significant relationship between psychophysical exhaustion (the dependent variable) and the emotional coping strategy. As a result, it turned out that a single increase in the emotional coping style (SSE) scale was accompanied by an increase in burnout by 0.48. It means that there is a directly proportional relationship between occupational burnout and emotional burnout and that verification of the SSE level will allow predicting the level of psychophysical exhaustion. Thus, the validity of the formulated hypothesis H.1 was confirmed. Table 3. Psychophysical exhaustion and styles of coping with stress-multiple regression model between psychophysical exhaustion (dependent variable) and three styles of coping with stress, task-focused style-SSZ, emotion-focused style-SSE, avoidance-focused style-SSU (independent variables). The high level of physical exhaustion in professional soldiers, caused by their emotional coping style, can be the result of spending a lot of energy on overcoming emotions and calming down.

The Relationship between the Style of Coping with Stress and the Sense of Commitment to Relationships with Clients
The obtained results (Table 4) allow us to conclude that the presented multiple regression model accurately reflects over 34% of the real relationships. This means, in the case of surveyed soldiers at the officer rank, a statistically significant possibility of predicting an increase in the lack of a sense of commitment to relationships with clients, based on the preference (expressed in the form of a specific index-scale category) of emotional coping style. So, hypothesis H.2 was confirmed. The lack of a sense of involvement in a relationship with contractors or other interlocutors among officers may result from excessive concentration on one's own emotions and experienced emotional tension.

The Relationship between the Style of Coping with Stress and the Feeling of Professional Ineffectiveness
The presented analysis of the multiple regression model (Table 5), once again in relation to the dependent variables that make up the level of occupational burnout (in the discussed case of the lack of a sense of professional effectiveness) showed the existence of a statistically significant relationship between the dependent variable and the emotional style of coping with stress. Thus, it can be expected that an increase in the emotional style of coping with stress scale by one value will result in an increase in occupational burnout by the highest value −0.52. In other words, the presented regression model explains over 50% of the actually existing relationships. Thus, it can be said with high probability that the H.3 hypothesis has been confirmed. Table 5. The sense of professional ineffectiveness and styles of coping with stress-multiple regression model between the sense of professional ineffectiveness (dependent variable) and three styles of coping with stress SSZ, SSE, SSU (independent variables). The preference of the emotional coping strategy with stress, which results in a feeling of lower professional effectiveness, has, unfortunately, great, unfavorable practical significance. The low effectiveness of the surveyed officers may lead to lower motivation to work, arouse discouragement, and limit creative initiative. (Table 6)

The Relationship between the Style of Coping with Stress and Disappointment
As in the previously discussed cases of dependencies between variables, the multiple regression analysis carried out confirmed the existence of a statistically significant relationship between the emotional coping strategy (as a dependent variable) and the level of disappointment related to the work performed by the participating soldiers with the officer rank. This means that a higher score on the emotional style of coping with stress leads to an increase in the level of disappointment, and the constructed model explains over 37% of the actually existing relationships. The obtained data (Table 6) allow confirming another hypothesis, H.4. Table 6. Disappointment and styles of coping with stress-multiple regression model between disappointment (dependent variable) and three styles of coping with stress SSZ, SSE, SSU (independent variables). The disappointment with the work performed, which may result from the mismatch between the expectations of officers and the experienced working conditions, is a factor which, as in the case of a lack of self-efficacy, reduces motivation to work and suppresses own invention, causing that in their work they will only do what is necessary [30,32,45].

The Relationship between the Style of Coping with Stress and the General Level of Occupational Burnout
The multiple regression model analysis (Table 7) showed that there is a directly proportional relationship between the emotional coping strategy (as a dependent variable) and the total level of occupational burnout (dependent variable). The obtained research result on the basis of an increase by one value of the SSE scale index allows predicting an increase in the level of occupational burnout by a value of over 0.51. Thus, the developed model explains more than 51% of the dependencies between variables and is therefore well suited to the dependence of real relationships. Thus, hypothesis H.5 was confirmed. Table 7. The level of occupational burnout (the sum of individual dimensions) versus styles of coping with stress-multiple regression model between occupational burnout (dependent variable) and three styles of coping with stress SSZ, SSE, SSU (independent variables).

Burnout in the Context of the Age of the Surveyed Officers
The analysis (Table 8) of the multiple regression model in the context of the included variables allows us to observe that the level of occupational burnout decreases with age, but this relationship is not statistically significant. However, assuming only the emotional style of coping with stress as the dependent variable and age as the independent variable, the proposed multiple regression model meets the criteria of acceptable statistical significance and explains more than 12% of the relationship (Table 9). This means that age may be a predictor of the emotional style of coping with stress preferences and an intermediary variable between the emotional coping style and professional burnout. Thus, the formulated hypothesis H.6., the existence of an inversely proportional relationship between age and occupational burnout, can only be considered partially confirmed.

Discussion of Results and Conclusions of the Research
The obtained research results confirmed the effects of previously performed studies on the role of the style of coping with stress as a factor limiting or increasing the occurrence of occupational burnout. The relationship between burnout and the experience of stress in public services was confirmed once again [63,64]. Although the research on the determinants of experiencing stress and burnout in most cases is not concerned with uniformed services, a relationship has been demonstrated that indicates the existence of such a relationship between coping with stress and occupational burnout [65]. The described research results confirm it.
Similar statements can be found in the conclusions of the research conducted by Rusu [66], which emphasized that, in line with the increase in seniority, the surveyed soldiers show lower and lower levels of burnout.
However, in the research by Nowakowska and colleagues [17], no correlation was found between the age and length of service of the respondents and the intensity of burnout features. These studies were carried out among students of emergency medicine and paramedics. It can be assumed that this situation is caused by the personality determinants of students and then graduates who decided to become a paramedic.
The obtained data collected among professional officers of the Polish Armed Forces clearly indicated the emotional style of coping with stress as resulting in an increase of the occupational burnout in its individual dimensions, as well as in occupational burnout as a whole.
The same result was found in the study by Vojevodic and colleagues [67], in the younger age group (23-30 years old) there was a higher level of emotional exhaustion compared to the older groups of participants (up to 53 years of age).
At the same time, it would be worth considering what conditions should be met for professional soldiers to choose styles of coping with stress other than their preferred ones. The preference of task-based coping with stress would mean that soldiers at the rank of officer could use the primary control, relating to the modification of external conditions of the work performed, not only to avoid stressors but also to use several different coping strategies. Preliminary evidence from work context theory supports the assumption that the use of primary control strategies continues to increase with work experience. Despite the fact that military service entails a number of limitations in taking any initiatives, it can be expected that professional soldiers at the rank of an officer have a certain possibility of shaping their working conditions (job crafting) and its implementation according to preferences, abilities, and possibilities. However, the obtained data showed that the dominant strategy turned out to be the emotional style of coping with emotional stress (SSE), as it can be assumed, based on a secondary strategy that requires "internal" modification of the originally set goals. Developmental theories of emotional regulation propose a stronger integration of cognition and emotions with increasing experience and professionalism [68,69]. For example, Labouvie-Vief et al. [68] argue that cognitive and affective processes develop separately and that the development of both types of processes continues in successive stages throughout life, with each stage building upon previous stages. Their integration facilitates both the regulation of emotions and social behavior [70]. Similarly, the theory of lifelong control [71] implies the use of secondary control strategies that develop throughout the work and private life cycle. For this reason, secondary control strategies, also referred to as coping with emotions [22], mean an internal influence on motivation, emotions, and mental representation.
In addition, the preference for the emotional style of coping with stress may result from the specificity of professional functioning of professional soldiers, related to the learned need to accept orders from superiors.
The obtained data confirmed the results of already conducted studies relating to the relationship between coping style, age, and occupational burnout. The confrontation of data with the previously conducted and obtained research results allows us to maintain the truth of the statement that the impact of stress at work on the functioning of employees differs depending on the period or stage of life in which it occurs [43][44][45][46].
In the presented context, the research conducted by Gotz et al. [47] provokes some controversy, who found the existence of a small, although statistically insignificant, relationship between age and experienced stress, so that older research participants turned out to experience stress to a slightly greater extent.
As a result of the research, the role of age and the related longer work experience as a factor allows predicting the choice of emotional style of coping with stress in a group of officers was confirmed.
Similar conclusions were also drawn by Soares and colleagues [72], who included demographic data, in particular age, personality, self-efficacy, and stress-coping styles among the factors that can mitigate the impact of stress at work on burnout and well-being. The obtained research results, in relation to the previously conducted research, also concern both the experience of stress and its relationship with occupational burnout.
Although they have not directly become the subject of research the obtained results, in a roundabout way, break the stereotypes existing in the social consciousness, which mean that employees with a longer period of service and over 40 years of age are perceived as less creative than their younger colleagues, with sometimes greater and excessively high expectations, generating greater problems in relationships, and less value as employees [7,8].
Considering the application aspects of the obtained research results, it can be observed that they indicate the need to build realistic self-esteem that allows developing a taskoriented style of coping with stress to a greater extent, which has a significant application dimension. It can be expected that it will be possible to optimize its building by gathering positive experiences, gaining feedback during the work performed, conducive to the development of one's own professionalism. This postulate applies both to the educational practice carried out during childhood and the personnel policy conducted among the personnel of the Polish Army. It can be expected that greater rewarding for manifestations of own invention and increasing autonomy, emphasizing achieved successes, appreciating officers, despite the fact that we are dealing with a militarized field, would contribute to increasing officers' self-efficacy, and thus increase the frequency of choosing a task-based strategy for coping with stress. The confirmed relationship between the emotional style of coping with stress and occupational burnout, treated as a personality variable, may find application in the recruitment and selection procedure for the officer profession in the Polish Army. At the same time, it should be borne in mind that the preference of such a strategy cannot be treated as the only factor that allows predicting the level of occupational burnout, as it may also result from the specificity of professional work of professional soldiers, in which a task-oriented style of coping with stress can be used in a more limited way than in other professions.
However, it is puzzling that Nakkas et al. [73] proved in their article that military candidates enjoyed a higher level of active stress-coping style than their peers. Similarly, in the previously quoted publication by Nowakowska and colleagues [17], rescue students chose the emotional style of coping with stress, and the older paramedics the task style. These preferences may result from the specificity of paramedics' work that requires making rational decisions in a situation of emotional stress, which in their case is not uncommon, but rather a normal situation.
Perhaps the preference for the emotional coping style among professional officers is due to the need to first adapt to existing procedures, and not to independently consider the possibility of solving the problem. Thus, it is likely that the surveyed officers perceived the task-oriented style of coping with stress as a style that goes beyond the applicable procedures.

Limitations and Directions of Future Research
The limitations of the research include the purposeful, i.e., limited by the consent of senior officers, selection of soldiers with the rank of research officer for research, a small research sample, and conducting research during the Covid-19 pandemic. Conducting research during a pandemic that generates a threat to health and sometimes life could be an additional factor having a negative impact on the level of occupational burnout and at the same time weaken the sense of personal effectiveness, which could become a source of more frequent task-oriented coping with stress. Moreover, one should be aware that the pandemic situation, due to the necessity to maintain the sanitary regime, limited the size of the research sample and the comfort of conducting the research, both on the part of people participating in the research and people who conducted the research.
The next stage of the research, as an implication of the research already carried out, would be to examine the personality determinants of the selection of a strategy of coping with stress as a next mediator of occupational burnout among professional soldiers, the effects of which could be applied in the recruitment and selection procedure for the soldier profession, as well as the relation of factors related to the specificity of work to personality determinants.  Institutional Review Board Statement: The study was conducted according to the guidelines of the Declaration of Helsinki, but was not approved by the Institutional Review Board, because the relevant committee was not appointed until October last year, while the research was carried out earlier. Currently, an application has been submitted to the Scientific Research Ethics Committee with a request to approve the research and the matter is being processed.

Informed Consent Statement:
The condition for the participation of the respondents in the research was the consent of the commanders of military units, and then the relevant authorities in the Ministry of National Defense.
Data Availability Statement: All data obtained from the research has not been made public and is in the authors' archives.