Generic military simulation of a complex workplace. A new tool for applied research in military settings.

In almost any military occupational specialty soldiers must monitor and react to stimuli, store and process information, make and communicate decisions, while using different in- and output modalities. When assessing influences on performance, e.g., by sleep-deprivation or heat-stress in intervention designs, researchers face a dilemma: They can either examine highly trained military experts in their jobs, thus risking limited generalizability of their results, or use standard measures of cognitive performance with little ecological relevance. To solve this dilemma, we developed a multidimensional job simulation by abstracting a wide range of military jobs into a generic military simulation of a complex workplace (GEMS COW). It had to meet the following requirements: 1) validly and reliably measure the relevant psychological constructs of the abstracted jobs, 2) require only minimal training, and 3) score high acceptance with military specialists. GEMS COW assesses attention, short-term memory (sm), and working memory (wm) in a lifelike setting. Three studies were conducted focusing on psychometric properties (Study 1, N = 74), overall task complexity in an intervention design (Study 2, N = 54), and acceptance (Study 3, N = 22) of GEMS COW. Psychometric properties proved satisfactory (construct validities: wm = .58, attention = .45, sm =.68; retest reliability: .61-.90). The simulation has a medium to high mental difficulty and soldiers accept it as a realistic military task. GEMS COW is easy to learn and reliably measures psychological constructs in a complex generic simulation. It can be used in intervention studies and may easily be implemented in other languages.

Index Finger Muscle Fatigue and Pistol Firing Failure.

OBJECTIVE: The aim of this study was to analyze finger strength and effects of muscle fatigue on the ability to shoot. BACKGROUND: The finger and hand muscles of soldiers are subject to high loads. For example, the trigger pull of military pistols can amount up to 58 N (≈6 kg) and could cause muscle fatigue in the trigger finger. For soldiers, however, maintaining the ability to shoot is essential for self-defense and survival. METHOD: The marksmanship training of 30 German soldiers (15 female) ages 18 to 40 years was evaluated. Three consecutive exercises with a total of 60 rounds were fired from target ranges of 5 and 10 m, equally using a single-action and double-action trigger mode. Maximum voluntary isometric contraction of the index finger (MVCIF) was measured before and after each of the three firing exercises. RESULTS: Shooting reduced MVCIF in female (88.2 ± 15.8 N to 67.3 ± 17.7 N, p < .001) and male soldiers (145.8 ± 21.7 N to 112.7 ± 26.6 N, p < .001). Of the 30 subjects, 23 were unable to shoot due to fatigue, including 15 of 15 female soldiers. The higher MVCIF was at rest, the less commonly (r = .73, p < .001) and the later (r = 0.82, p < .001) task failure occurred. Two intermissions of approximately 6 min did not suffice for a significant recovery. CONCLUSION: Excessive trigger pull weight causes muscle fatigue of the index finger and can ultimately lead to task failure during pistol marksmanship training. Short breaks are insufficient for the recovery of finger muscles. APPLICATION: This study presents a new perspective on ideal trigger pull weight, which should be carefully considered by manufacturers to allow repetitive firing and simultaneously ensure safe handling.

Strength Training for Women as a Vehicle for Health Promotion at Work.

BACKGROUND: Women, on average, have less muscle strength than men. This anthropometric-physiological trait may make them more vulnerable to ex - cessive physical strain, injury, and inability to work. Strength training is used for preventive health maintenance and to lessen musculoskeletal symptoms. In this context, we studied whether the degree of muscle strength has any effect on women's health in everyday working life, and also the effects of strength training for women on their health in the workplace. METHODS: We systematically searched the PubMed/MEDLINE, Embase, CINAHL, Web of Science, CENTRAL, and SPOLIT databases for pertinent publications, in accordance with the PRISMA criteria for literature searches. We analyzed all of the retrieved randomized controlled trials conducted on women aged 18 to 65 to determine the effects of training on muscle strength, physical performance ability, and health-related parameters including body composition, musculo - skeletal pain, and subjective well-being. RESULTS: We did not find any studies that provided answers to the first question. As for the second question, the selection criteria were met by 12 of the 4969 retrieved studies, which dealt with the effect of strength training on health in the occupational environment and involved a total of 1365 female subjects. These studies were carried out in heterogeneous subject groups, with a variety of overlapping interventions consisting of both strength and endurance training. Significantly increased strength was found in all studies, as was a reduction of pain in all of the studies where this question was asked. Inconsistent results were obtained with respect to body weight, body composition, and subjective well-being. CONCLUSION: The interventions that were conducted in these studies succeeded in increasing strength and reducing pain, even when the training was brief and of low intensity. This was true not only for women working in occupations requiring unusual physical strength, but also for those in sedentary occupations. The small number of studies performed on this subject to date is surprising in view of the high prevalence of musculoskeletal symptoms in women.

Even One Is Too Much: Sole Presence of One of the Risk Factors Overweight, Lack of Exercise, and Smoking Reduces Physical Fitness of Young Soldiers.

Health and physical fitness are key factors for soldiers. Increased sedentary military work, significant sitting periods during commuting and leisure time, and unhealthy dietary habits have caused a considerable increase in the number of physically unfit soldiers. Even worse, the adoption of harmful lifestyle habits occurs increasingly earlier in life. The aim of this cross-sectional study was (a) to determine the physical fitness of young male soldiers and (b) to investigate the association between physical fitness and both the presence and frequency of the health risk factors overweight, smoking, and lack of exercise. A total of 4,553 volunteers aged 18-25 years performed the Basis Fitness Test consisting of the 3 disciplines agility (11 × 10 m shuttle sprint), strength (flexed-arm hang), and endurance (1,000-m run). The presence and frequency of risk factors were determined by means of anthropometric measures (body mass index, waist circumference) and questionnaire data. The portion of soldiers without risk factors decreased from 49.4% (18-year-olds) to 16.4% for 25-year-olds. Persons without risk factors completed the agility test in 41.1 ± 3.7 seconds, flexed-arm hang in 60.1 ± 19.7 seconds, and 1,000-m run in 235 ± 32 seconds. Physical performance in all dimensions tested (agility, strength, endurance) notably deteriorated with the sole presence of one of the risk factors overweight, smoking, and lack of exercise. Any further risk factor led to further fitness decreases (p < 0.001). Mean performances of soldiers with 3 risk factors were 46.7 ± 4.1 seconds (11 × 10 m shuttle sprint), 27.6 ± 6.4 seconds (flexed-arm hang), and 298 ± 45 seconds (1,000-m run). Impacts of unhealthy lifestyles and significant losses in physical fitness are already visible in young male soldiers. Armed Forces must intensify their efforts to maintain health and performance of their soldiers.

Concept for a Predeployment Assessment of Basic Military Fitness in the German Armed Forces.

Military fitness is defined as a hierarchical 4-level construct in the German armed forces: (a) "Fundamental/Baseline Fitness," (b) "Basic Military Fitness," (c) "Task Fitness," and (d) "Mission Fitness." "Fundamental/Baseline Fitness" is assessed with the "Basic Fitness Test." However, this test alone is not sufficient to assess readiness for the physical demands of deployments. The first part of the article describes the development of a tool mirroring the specific physiological requirements of military operations on a joint forces level. The "Basic Military Fitness Tool" (BMFT) combines 4 crucial military demands into one single timed test run performed with field uniform (5 kg), body armor (13.4 kg), and helmet (1.6 kg): (a) maneuver under fire: 130 m run with changes in direction, velocity, and body position, (b) casualty rescue: 40 m of dragging a 50 kg load, (c) load carrying: 100 m carrying of two 18 kg loads, and (d) load lifting: lifting a 24 kg load on to a 1.25 m high rack 5 times. The second part covers the first assessment of BMFT selectivity between high- and low-performing groups. Muscle mass and strength are important factors for working with loads. Thus, female soldiers are expected to need more time to complete BMFT because of their on average lower muscle mass. Eighteen female (age = 28.5 ± 6.6 years, lean body mass [LBM] = 45.0 ± 4.5 kg; mean ± SD) and 104 male soldiers (age = 30.0 ± 8.4, LBM = 64.3 ± 7.1) completed isometric strength testing (hand grip = 344.3 ± 51.4 N and 547.3 ± 79.1 N, elbow flexors = 118.9 ± 16.9 and 235.1 ± 42.0, knee extensors = 433.2 ± 87.4 and 631.4 ± 111.4) and BMFT (259.2 ± 44.0 and 150.0 ± 21.1 s). Except age, all variables differed significantly (p < 0.01) between groups.

Results of a workplace health campaign: what can be achieved?

BACKGROUND: Effective health promotion in the workplace is now essential because of the rising health-related costs for businesses, the increasing pressure arising from international competition, prolonged working lives, and the aging of the work force. The basic problem of prevention campaigns is that the target groups are too rarely reached and sustainable benefits too rarely achieved. In 2011, we carried out a broad-based health and fitness campaign to assess how many personnel could be motivated to participate in a model study under nearly ideal conditions. METHOD: 1010 personnel were given the opportunity to participate in various kinds of sports, undergo sports-medicine examinations, attend monthly expert lectures, and benefit from nutritional offerings and Intranet information during work hours. Pseudonymized questionnaires were used to classify the participants according to their exercise behavior as non-active, not very active, and very active. The participants' subjective responses (regarding, e.g., health, exercise, nutrition, and the factors that motivated them to participate in sports or discouraged them from doing so) were recorded, as were their objective data (measures of body size and strength). The duration of the study was one year. RESULTS: 490 of the 1010 personnel (48.5%, among whom 27.2% were nonactive, 44.1% not very active, and 28.7% very active) participated in the initial questionnaire and testing. By the end of the study, this figure had dropped to 17.8%; diminished participation affected all three groups to a comparable extent. A comparison of dropouts and non-dropouts revealed that older age was a stable predictor for drop-out (bivariate odds ratio [OR] 1.028, p = 0.006; multivariate OR 1.049, p = 0.009). The study participants reported beneficial effects on their health and health awareness, performance ability, psychological balance, stress perception, exercise and dietary behavior. CONCLUSION: Even under optimal conditions and with high use of staff resources, this model study (which cannot be universally implemented) did not lead to comprehensive and sustained personnel participation. This finding suggests that the currently available prevention instruments are insufficient for the effective and cost-efficient promotion of health and fitness in the workplace.

Physical fitness, weight, smoking, and exercise patterns in young adults.

INTRODUCTION: The health and physical fitness of adolescents and young adults are important not just to the individuals concerned, but also to society as a whole. Many studies from many different countries have dealt with the prevalence of overweight, the risk factors for it, and the morbidity it causes, but no more than a few have addressed the effects of unhealthy lifestyles on physical fitness. In this study, we show that young adults' physical performance depends on the number of risk factors they possess. We also compare the young adults' physical performance with that of adolescents aged 10 to 17. METHODS: We obtained cross-sectional data on the weight, smoking status, athletic activity, time to run 1 km, and ability to perform a chin-up on a horizontal bar of 8048 subjects aged 10 to 25. The young adults were divided into groups depending on the number of risk factors they possessed from the following list: overweight, smoking, and lack of exercise. RESULTS: 28.4% of the men and 35.4% of the women aged 18 to 25 had none of these risk factors and exhibited the best physical performance. The more risk factors were present, the worse physical performance became. The 24- and 25-year-olds performed at the same level as the 14- and 15-year-olds. DISCUSSION: Unhealthy lifestyles can impair physical fitness even before any chronic disease arises. Possession of even a single risk factor is associated with significantly worse performance. Unless comprehensive and effective interventions are introduced in school and at work, the further cementation and worsening of unhealthy lifestyles will be hard to stop.

Importance of sports during youth and exercise barriers in 20- to 29-year-old male nonathletes differently motivated for regular physical activities.

The number of sedentary young adults has dramatically increased in past decades, and sedentary lifestyles are adopted at an increasingly earlier age. Little is known about barriers or predictors to (re)initiate regular physical activity in this group. The purpose of the study is to (a) identify subgroups in nonathletes differing in their amenability to physical exercise, (b) to analyze them for differences in barriers and intention to exercise, and (c) compare importance of sports during youth in nonathletes to trained peers. Using a health and fitness questionnaire 589 nonathletes were queried in the cross-sectional survey and compared with 270 trained peers. Athletic abstainers (A), lower (L), and higher (H) motivated nonathletes were separated based on previous engagement in sports. Of the nonathletes, 54.7% reported only 1 barrier to exercise. Although this feature was most prominent in H (71.5%), the other groups showed significantly more barriers and a broader distribution. Similar characteristics but minor differences were observed for perceived importance of sports during youth. The most significant differences between athletes and nonathletes emerged enquiring the attitude and activity of the parents. The majority of nonathletes (72.8%) indicate their intention to exercise in the future. Their intention differed significantly in H (88.1%), L (76.1%), and A (59.1%). However, there are good reasons to doubt that most of those intending nonathletes will actually become physically active. Even in the analyzed narrow age range of men different motivated groups of nonathletes were found. Because of the differences in receptiveness and approachability health promotion policies may not only consider the often recommended tailored interventions but also carefully designed incentive programs.

Physical performance in middle age and old age: good news for our sedentary and aging society.

BACKGROUND: Physical performance often declines in middle age, but it is unclear to what extent this is due to biological aging. It can be difficult to determine whether such physical changes are truly age-related, as they might alternatively be explained as the negative consequences of a sedentary lifestyle. METHODS: We assessed the endurance of a physically active subgroup of the population by performing an age- and sex-stratified analysis of over 900,000 running times of marathon and half-marathon participants aged 20 to 79. We also analyzed the responses of 13,171 marathon and half-marathon runners to a questionnaire about sports, lifestyle, and health. RESULTS: No significant age-related decline in performance appears before age 55. Moreover, only a moderate decline is seen thereafter; in fact, 25% of the 65- to 69-year-old runners were faster than 50% of the 20- to 54-year-old runners. Our survey also revealed that more than 25% of the 50- to 69-year-old runners had started their marathon training only in the past 5 years. CONCLUSION: Performance losses in middle age are mainly due to a sedentary lifestyle, rather than biological aging. The large contingent of older "newcomers" among marathon runners demonstrates that, even at an advanced age, non-athletes can achieve high levels of performance through regular training.

Field dependence-independence from a working memory perspective: A dual-task investigation of the Hidden Figures Test.

Field dependence-independence (FDI) is a construct intensively investigated within cognitive style research, but its cognitive underpinnings are not clearly specified. We propose that performance on FDI tasks primarily reflects the operations of the visuospatial and executive components of working memory. We tested this hypothesis in a dual-task experiment with a commonly used measure of FDI, the Hidden Figures Test. The results showed that performance on this test was impaired by concurrent performance of secondary tasks that primarily tap the visuospatial component (spatial tapping) and the executive component (2-back and random number generation), but was almost unaffected by other secondary tasks (simple tapping and articulatory suppression). Moreover, an analysis of secondary task performance ruled out the possibility of strategic trade-offs and revealed an intriguing dissociation for two different sets of "randomness" indices for the random number generation task. These results support the hypothesised mapping between FDI and working memory components and suggest that the dual-task paradigm can provide a useful way to bring underspecified constructs like FDI into closer alignment with theoretical ideas developed within cognitive psychology.