Anthropometrics, body composition, and aerobic fitness in Norwegian home guard personnel.

The Norwegian Home Guard (HG) consists of soldiers and officers who primarily live a civilian life but are typically called in for military training a few days per year. Although full-time soldiers and officers are monitored annually on physical fitness, no such assessments are performed on regular HG personnel. Data on physical fitness of similar forces from other nations are also scarce. Thus, the main aim of this study was to collect reference data on physical fitness in HG personnel. A total of 799 male soldiers and officers from the regular and the rapid reaction HG force participated in this study. Between 13 and 19% of the subjects were obese, according to measured body mass index, waist circumference and estimations of body fat. The mean (95% confidence interval) estimated peak oxygen uptake from the 20-m shuttle run test was 50.1 (49.7-50.6) mL·kg·minute. Personnel from the rapid reaction force had a more favorable body composition compared with the regular HG personnel, whereas no differences were found for peak oxygen uptake. The physical demands on HG personnel are not well defined, but we believe that the majority of Norwegian HG soldiers and officers have a sufficient aerobic fitness level to fulfill their planned HG tasks. The gathered data can be used by military leaders to review the ability of the HG to perform expected military tasks, to serve as a future reference material for secular changes in HG fitness level, and for comparison purposes among similar international reserve forces.

Change in anthropometrics and aerobic fitness in Air Force cadets during 3 years of academy studies.

INTRODUCTION: Favorable anthropometrical status and aerobic fitness levels are emphasized in Norwegian Air Force personnel. However, it is unknown how these variables develop in Air Force cadets. Thus, the main aim of the present study was to examine how anthropometrics and maximal oxygen uptake (VO2(max)) change among Norwegian Air Force cadets during 3 yr of Academy studies. METHODS: There were 30 male cadets included in the study. Bodyweight, body mass index (BMI), estimated percent body fat, and VO2(max) were measured at entry and at the end of the first year of Academy studies. After the first year, 14 cadets left the Academy, while the remaining cadets were retested at the end of the second and third years. RESULTS63: At entry, mean (95% CI) bodyweight, BMI, percent body fat, and VO2(max) were 78.4 (75.2, 81.6) kg, 24.3 (23.5, 25.1) kg x m(-2), 17.8 (16.3, 19.3)%, and 4.48 (4.25, 4.72) L x min(-1), respectively. Percent body fat decreased significantly by 1.1 (0.2, 2.0) percentage points at the end of the first year, while the other variables did not change during the first year. Between entry and end of third year there was no change in any of the main outcome variables. DISCUSSION: Anthropometrical status and VO2(max) did not change in Norwegian Air Force cadets between entry and the end of 3 yr of Air Force Academy studies. From the 1- and 3-yr follow-up analysis, the only significant change was a small reduction in estimated percent body fat from entry to the end of the first year.

Change in Anthropometrics and Physical Fitness in Norwegian Cadets During 3 Years of Military Academy Education.

INTRODUCTION: High physical fitness is associated with increased occupational performance, better health, and reduced risk of injuries in military personnel. Thus, the military emphasizes physical training to maintain or develop physical fitness in their soldiers. It is important to monitor the effect of the physical training regime, but such information is lacking for Norwegian military cadets. Hence, the primary aim of this study was to investigate changes in anthropometrics and physical fitness among male and female army, navy and air force cadets during 3 years of military academy education. MATERIALS AND METHODS: 260 male and 29 female Norwegian cadets from the army, navy, and air force academies volunteered to participate. Anthropometrics, muscular power, muscular endurance, and maximal oxygen uptake were measured at entry (T0) and end of each year (T1, T2, and T3). Linear mixed models were used to examine the development in anthropometrics and physical fitness. We applied to the Regional Committee for Medical and Health Research Ethics to review the study before start-up, but the study was considered exempted from notification. The study was reviewed and approved by the Norwegian Social Science Data Services. RESULTS: Male and female cadets significantly increased their body weight, fat-free mass, body mass index, and percent body fat by 1 to 5% from T0 to T3. Skeletal muscle mass was unchanged. Muscular power (medicine ball throw and vertical jump) and muscular endurance (pull-ups and push-ups) increased by 3 to 20% in male cadets, while female cadets only increased results significantly for the medicine ball throw (10%). Relative maximal oxygen uptake decreased by 4% in both sexes, while absolute maximal oxygen uptake only decreased significantly (by 2%) in male cadets. Most of the observed changes were classified as trivial or small, according to calculated effect sizes. The observed changes were generally of similar magnitude for male and female cadets, and similar among the three academies. CONCLUSIONS: Anthropometrics and physical fitness were relatively stable in Norwegian male and female army, navy, and air force cadets during 3 years of military academy education. Observed changes were typically classified as trivial or small. The initial gap in physical fitness between male and female cadets did not narrow during the education years. Norwegian male and female cadets displayed relatively good physical fitness profiles, compared to sex-matched cadets and soldiers from previously studied military populations.

Reliability and Validity of a Maximal Treadmill Test for Predicting Aerobic Fitness in Norwegian Prospective Soldiers.

INTRODUCTION: The Norwegian armed forces reintroduced physical fitness testing of prospective conscript soldiers in 2011. Since then, a customized maximal treadmill test (MILMAX) has been used to screen aerobic fitness in 15-20,000 young Norwegian men and women annually. The aim of the current study was to investigate reliability and validity of the MILMAX test. MATERIALS AND METHODS: Sixty-seven young Army recruits (including 11 women) participated in this method comparison study. The subjects completed the MILMAX test twice (test-retest), consisting of walking and running at increasing speed and inclination until voluntarily exhaustion. Performance was registered as exercise tolerance time (ETT). Later, the subjects performed a treadmill test of direct maximal oxygen uptake (V̇O2max). All tests were conducted within 15 days. The study protocol was submitted to the Regional Committee for Medical and Health Research Ethics for review, prior to study initiation. The Committee considered the study to be exempted from notification. The study was carried out according to the guidelines in the Declaration of Helsinki. RESULTS: There was no significant mean difference in MILMAX ETT between test and retest. Test-retest intraclass correlation coefficient was 0.95 (0.91, 0.97), while 95% limits of agreement was ± 60 seconds. Regression analyses showed that MILMAX ETT and gender explained 78% of the variance in directly measured V̇O2max, and a prediction equation with these two independent variables was generated. The Pearson correlation coefficient between predicted and directly measured V̇O2max was 0.89 (0.83, 0.93), while limits of agreement was ± 5.6 mL·kg-1·min-1. CONCLUSIONS: The MILMAX is equally reliable and valid compared with well-known maximal indirect tests like the 2-mile run and the 20-m shuttle run test, and may serve as an alternative indoor test of aerobic fitness in the military, in other potentially physically strenuous occupations, or in healthy civilians.

Objectively Measured Physical Activity in Home Guard Soldiers During Military Service and Civilian Life.

Soldiers are encouraged to be physically active, and thereby maintain or increase their fitness level to meet job-related physical demands. However, studies on objectively measured physical activity (PA) in soldiers are scarce, particular for reserve soldiers. Hence, the aim of this study was to present PA data on Norwegian Home Guard (HG) soldiers. A total of 411 HG soldiers produced acceptable PA measurements (SenseWear Armband Pro2) during civilian life, of which 299 soldiers also produced acceptable data during HG military training. Reference data on total energy expenditure, metabolic equivalents, steps per day, and minutes of PA in three different metabolic equivalent categories are presented. The HG soldiers produced more minutes of moderate PA during HG military training compared to civilian life, but less vigorous and very vigorous PA. Furthermore, HG soldiers were more physically active during civilian week days compared to weekend days. The presented reference data can be used for comparisons against other groups of soldiers. Our data indicate that aerobic demands during HG military training were not very high. Promoting PA and exercise could still be important to ensure HG soldiers are physically prepared for more unforeseen job tasks.

Validity and reliability of bioelectrical impedance analysis and skinfold thickness in predicting body fat in military personnel.

Previous studies show that body composition is related to injury risk and physical performance in soldiers. Thus, valid methods for measuring body composition in military personnel are needed. The frequently used body mass index method is not a valid measure of body composition in soldiers, but reliability and validity of alternative field methods are less investigated in military personnel. Thus, we carried out test and retest of skinfold (SKF), single frequency bioelectrical impedance analysis (SF-BIA), and multifrequency bioelectrical impedance analysis measurements in 65 male and female soldiers. Several validated equations were used to predict percent body fat from these methods. Dual-energy X-ray absorptiometry was also measured, and acted as the criterion method. Results showed that SF-BIA was the most reliable method in both genders. In women, SF-BIA was also the most valid method, whereas SKF or a combination of SKF and SF-BIA produced the highest validity in men. Reliability and validity varied substantially among the equations examined. The best methods and equations produced test-retest 95% limits of agreement below ±1% points, whereas the corresponding validity figures were ±3.5% points. Each investigator and practitioner must consider whether such measurement errors are acceptable for its specific use.