Body composition and military performance--many things to many people

Defining Overweight and Obesity by Percent Body Fat Instead of Body Mass Index

OBJECTIVE

Thresholds for overweight and obesity are currently defined by body mass index (BMI), a poor surrogate marker of actual adiposity (percent body fat [%BF]). Practical modern technologies provide estimates of %BF but medical providers need outcome-based %BF thresholds to guide patients. This analysis determines %BF thresholds based on key obesity-related comorbidities, exhibited as metabolic syndrome (MetSyn). These limits were compared to existing BMI thresholds of overweight and obesity.

DESIGN

Correlational analysis of data from cross sectional sampling of 16 918 adults (8734 men and 8184 women) from the US population, accessed by the National Health and Nutrition Examination Survey public use datasets.

RESULTS

Individuals measured by BMI as overweight (BMI > 25 kg/m2) and with obesity (BMI > 30 kg/m2) included 5% and 35% of individuals with MetSyn, respectively. For men, there were no cases of MetSyn below 18%BF, %BF equivalence to "overweight" (ie, 5% of MetSyn individuals) occurred at 25%BF, and "obesity" (ie, 35% of MetSyn individuals) corresponded to 30%BF. For women, there were no cases of MetSyn below 30%BF, "overweight" occurred at 36%BF, and "obesity" corresponded to 42%BF. Comparison of BMI to %BF illustrates the wide range of variability in BMI prediction of %BF, highlighting the potential importance of using more direct measures of adiposity to manage obesity-related disease.

CONCLUSION

Practical methods of body composition estimation can now replace the indirect BMI assessment for obesity management, using threshold values provided from this study. Clinically relevant "overweight" can be defined as 25% and 36% BF for men and women, respectively, and "obesity" is defined as 30% and 42% BF for men and women.

US Army Accession and Retention Standards: Impact on Obesity and Medical Readiness

INTRODUCTION

Military body fat standards were implemented in the 1980s to prevent obesity and associated poor military readiness. In the past 2 decades, enforcement of existing Army body composition standards has been eroded by the steady increase in national obesity rates, the demand for new recruits especially during the 2007 surge in Iraq, and the COVID epidemic in 2020. The diminishing qualified recruit pool puts a new focus on accession standards. The purpose of accession standards is to ensure that recruits will meet soldier standards, but accession standards have been relaxed to improve recruitment with an assumption that most recruits will achieve the retention standards during initial entry training. A new method of percent body fat estimation (%BF) adopted by the Army in 2024 further liberalizes both accession and retention standards. This study examined the impact of current accession and retention %BF standards on the proportion of the US population that would be disqualified from Army service.

METHODS

This analysis was based on National Health and Nutrition Examination Survey (NHANES) statistical sampling of the US population, where height, weight, abdominal circumferences, and dual-energy x-ray absorptiometry (DXA) %BF data were available (n = 26,090, including 13,302 men and 12,788 women). The proportion of individuals in the NHANES data failing to meet weight screen and %BF standards based on age and sex categories were calculated using DXA and the new Army anthropometric method. A recent large dataset from another service was used to compare the new method to DXA.

RESULTS

Near one-third to one-half of American men and women failed to meet the current Army body composition standard (29, 39, 48, and 50% of men and 39, 45, 46, and 50% of women for age groups 17-20, 21-27, 28-29, and 40-59). More men than women benefited from more liberal accession standards to enter the Army above the retention standard to which they will be held after initial entry training (an additional 12, 11, 15, and 15% of men and 7, 1, 2, and 1% of women who met accession standards exceeded retention standards and would be expected to lose %BF after entry). Approximately one-fourth of women exceeded %BF but were under the height-weight screen; <10% of men were in this category. No men but 16% of the youngest women had low lean mass (<35 kg).

DISCUSSION

Army body composition standards are generous, extending to the limits of increased metabolic health risks and providing underestimates of actual %BF based on the behavior of circumference-based methods of body fat estimation. However, current standards do not accurately select or track physical readiness, especially for women, and should be updated. Modernization of physical readiness standards to meet the needs of the Army of 2030 could include adoption of new technologies that directly assess central adiposity, adequate muscle mass, and replace fitness testing with cardiac output metrics. With half of US adults projected to be obese by 2030, it is time for a review of the strategic goals of modernized military readiness standards.

Injury Profiling in Male Police Cadets During Initial Training Phase: A Retrospective Cohort Study

Musculoskeletal injuries during the "Initial Training Phase" (ITP) are a major medical problem faced by law enforcement agencies worldwide. Aiming to develop an injury prevention strategy, we examined the incidence, type, associated factors, and severity of injuries and secondarily tracked their evolution over time by batches in a police academy. A retrospective cohort study was conducted using prospectively collected injury data on 979 newly recruited male police cadets enrolled in eight batches between 2015 and 2023. Among the 376 injured participants (age: 18.1 ± 0.3 years, body-mass: 75.8 ± 12.5 kg, body-height: 173.7 ± 4.0 cm, body mass index [BMI]: 25.1 ± 4.1 kg·m-2, body-fat percentage: 18.1% ± 5.1%), 405 injuries were recorded during the ITP. Musculoskeletal injury data were analyzed according to type, associated-factors, severity, and evolution across batches. Almost half of the recruits (41.4%) sustained at least one musculoskeletal injury. Based on injury frequency (39-69 case) and exposure time (20,944.5-43,006.5 hours per participant) indices, and with an implication of scientific training tips, the long-term follow-up over-batches showed that the injury incidence was decreased 2.5-fold from Batch 1 to Batch 8 (p < .0001). Most injuries occurred between Weeks 2 and 5 (80% cumulative). The most common injury type was medial tibial stress syndrome (36.0%), followed by iliotibial band syndrome (12.6%), and ankle sprain (10.4%). This injury profile aligns with previous studies on law enforcement recruits, although comparisons should be made cautiously due to variations in training programs and recruit characteristics between agencies. The most frequently reported perceived potential contributors of injuries were vitamin and mineral deficiencies (20.7%), overweight/obesity (19.1%), and harsh physical activities (13.0%). During ITP, almost half of the recruits sustained at least one musculoskeletal injury, most of them in the fourth week. Some of the major associated factors of injury could be controlled resulting in a potential reduction of the injury incidence by up to 2.5 times. Implementing tailored fitness programs, incorporating subjective and objective training load assessments, and enhancing monitoring could significantly decrease injury rates, improve recruit readiness, and reduce resource and time waste on injury treatment.

Psychological endurance: how grit, resilience, and related factors contribute to sustained effort despite adversity

Many concepts describe how individuals sustain effort despite challenging circumstances. For example, scholars and practitioners may incorporate discussions of grit, hardiness, self-control, and resilience into their ideas of performance under adversity. Although there are nuanced points underlying each construct capable of generating empirically sound propositions, the shared attributes make them difficult to differentiate. As a result, substantial confusion arises when debating how these related factors concomitantly contribute to success, especially when practitioners attempt to communicate these ideas in applied settings. The model proposed here-psychological endurance-is a unified theory to explore how multiple concepts contribute to sustained goal-directed behaviors and individual success. Central to this model is the metaphor of a psychological battery, which potentiates and sustains optimal performance despite adversity. Grit and hardiness are associated with the maximum charge of the psychological battery, or how long an individual could sustain effort. Self-control modulates energy management that augments effort required to sustain endurance, whereas resilience represents the ability to recharge. These factors are constrained by both psychological and physiological stressors in the environment that drain the psychology battery. Taken together, these ideas form a novel framework to discuss related psychological concepts, and ideally, optimize intervention to enhance psychological endurance.

The 300 Marines: characterizing the US Marines with perfect scores on their physical and combat fitness tests

Few US Marines earn perfect 300 scores on both their Physical Fitness Test (PFT) and Combat Fitness Test (CFT). The number 300 invokes the legendary 300 Spartans that fought at the Battle of Thermopylae, which inspired high physical fitness capabilities for elite ground forces ever since.

Purpose

Determine distinguishing characteristics of the "300 Marines" (perfect PFT and CFT scores) that may provide insights into the physical and physiological requirements associated with this capability. These tests have been refined over time to reflect physical capabilities associated with Marine Corps basic rifleman performance.

Materials and methods

Data were analyzed from US Marines, including 497 women (age, 29 ± 7 years; height 1.63 ± 0.07 m; body mass, 67.4 ± 8.4 kg) and 1,224 men (30 ± 8 years; 1.77 ± 0.07 m; 86.1 ± 11.1 kg). Marines were grouped by whether they earned perfect 300 scores on both the PFT and CFT (300 Marines) or not. We analyzed group differences in individual fitness test events and body composition (dual-energy x-ray absorptiometry).

Results

Only 2.5% (n = 43) of this sample earned perfect PFT and CFT scores (n = 21 women; n = 22 men). Compared to sex-matched peers, 300 Marines performed more pull-ups, with faster three-mile run, maneuver-under-fire, and movement-to-contact times (each p < 0.001); 300 Marines of both sexes had lower fat mass, body mass index, and percent body fat (each p < 0.001). The lower percent body fat was explained by greater lean mass (p = 0.041) but similar body mass (p = 0.085) in women, whereas men had similar lean mass (p = 0.618), but lower total body mass (p = 0.025).

Conclusion

Marines earning perfect PFT and CFT scores are most distinguished from their peers by their maneuverability, suggesting speed and agility capabilities. While both sexes had considerably lower percent body fat than their peers, 300 Marine women were relatively more muscular while men were lighter.

Relationships Between Anthropometric Measures and Body Composition With Individual ACFT Event Performance Among Army Reserve Officers' Training Corps Cadets

ABSTRACT

Thompson, MB, Lawson, DJ, Orr, RM, Lockie, RG, and Dawes, JJ. Relationships between anthropometric measures and body composition with individual ACFT event performance among army reserve officers' training corps cadets. J Strength Cond Res 38(4): 749-754, 2024-The U.S. military commonly uses body composition as an indicator of a soldier's potential to meet the physical demands required of their occupation. The purpose of this study was to determine whether significant relationships existed between select body composition variables and Army Combat Fitness Test (ACFT) performance among a cohort of university Army Reserve Officers' Training Corps (ROTC) cadets. Twenty-six male (20.4 ± 1.6 years, 81.8 ± 8.5 kg, 178.3 ± 7.8 cm) and 12 female (19.9 ± 1.4 years, 64.2 ± 6.7 kg, 161.9 ± 4.9 cm) cadets voluntarily participated in this study. Body composition was measured using bioelectrical impedance analysis, and ACFT event scores were recorded by the cadre using the U.S. Army standard protocol and provided to the investigators. Pearson's correlations were used to identify relationships between body composition variables and ACFT event performance with an alpha level of p ≤ 0.05. Moderate to strong relationships were observed between total body water, dry lean mass, lean body mass, skeletal muscle mass, body fat mass (FM), and body fat percentage and all event scores for the sample as a whole. Body mass index showed weak to moderate significant positive relationships with hand-release push-up and maximum hexagonal bar deadlift in the sample as a whole. No relationships were observed in the men of this sample. All body composition variables showed moderate, nonsignificant relationships with at least 1 ACFT event within the women of this sample. Considering the findings of this study, a multitude of variables could be useful to assess ROTC cadets as predictors for ACFT performance. Reserve Officers' Training Corps programs should emphasize attaining and maintaining functional lean mass, whereas reducing nonfunctional body mass (i.e., excess FM) among cadets to enhance health and performance across the occupational life span.

Validity and reliability of portable A-mode ultrasound in measuring body fat percentage: A systematic review with meta-analysis

The present Systematic Review with Meta-analysis study aimed to evaluate the validity and reliability of the Portable A-mode Ultrasound (P-US) for measuring body fat percentage (BF%). Only studies with participants of both genders which had assessed BF% using P-US compared to the reference standard were selected. Publications up until May 31, 2022 were searched in the MEDLINE, COCHRANE, Science Direct, Web of Science, LILACS, SciELO, PEDro, SPORT Discus, CINAHL and SCOPUS databases. QUADAS-2 was used to assess the risk of bias in the validity studies and QAREL was used for the methodological quality of reliability studies. The JAMOVI software program synthesized the results, from which the Pearson Correlation Coefficient (r) or the square root of the Multiple Linear Regression Determination Coefficient (R2) were extracted for the validity studies, and the Mean of Errors of the Bland-Altman Test (ME) and the Confidence Interval (95%CI) with Upper and Lower Limits for the reliability studies. A total of 13 studies were included, generating 26 results for the quantitative synthesis, 14 for validity and 12 for reliability. Regarding the validity results, a strong correlation was identified between the equipment (r = 0.870 [0.845-0.895], P<0.001), with moderate and true heterogeneity (I2 = 53.47%, P = 0.003), presenting publication bias. A small effect size was identified regarding the reliability results, overestimating the results due to chance between the devices (ME = 0.207 [-0.798-1.212], P = 0.686), with low heterogeneity also due to chance (I2 = 19.44%, P = 0.253), with no publication bias. All of the evaluated studies showed some violation of the instruments, confirming the high risk of bias and the low methodological quality. There is concern with heterogeneity for the validity results explained by the subgroups' analysis. The P-US associated with anthropometric perimeters satisfactorily measures the BF% with samples greater than 100 participants, and males. The results in the reliability assessment show high agreement and high variability, greatly expanding the confidence interval, which should be viewed with reservations. This review received financial support from the Brazilian Air Force. The study was registered with PROSPERO under the number CRD42020166617.

Associations Among Stress, Internalized Weight Stigma, Emotional Eating, and Body Composition in Active-Duty Service Members Enrolling in a Randomized Controlled Trial of a Weight Management Program

BACKGROUND

Obesity is a critical public health concern with particular relevance to US military personnel. Stress and internalized weight stigma ("stigma") may contribute to and maintain obesogenic processes and behaviors, including emotional eating. In this secondary cross-sectional analysis, we examined (1) associations among stress and stigma with emotional eating and body fat percentage (BF%), (2) whether stress explains the association between stigma and emotional eating, and (3) whether emotional eating explains associations between stress and stigma with BF%.

METHOD

Active-duty military service members (N = 178) completed BF% assessment and questionnaires assessing stress, stigma, and emotional eating.

RESULTS

Structural equation modeling path analyses showed that stress and stigma were both significantly associated with emotional eating (b = 0.35, p < 0.001 and b = 0.23, p < 0.001, respectively) and with BF% (b = 0.38, p < 0.001 and b = 0.29, p < 0.001, respectively) such that individuals who reported higher stress and stigma tended to report more emotional eating and had higher BF%. Stress partially explained the association between internalized weight stigma and emotional eating, and emotional eating partially explained the relationship between stress and BF% but did not significantly mediate the association between stigma and BF%.

CONCLUSION

Greater stress and internalized weight stigma were associated with more emotional eating and higher BF%; however, emotional eating only partially explained the association between stress and BF%. Results highlight the importance of interventions targeting stress management skills, but additional research is needed to identify mechanisms that explain the association between stigma and BF%.

Comparing Body Composition Methods for Air Force Reserve Officers' Training Corps Cadets

INTRODUCTION

In special populations, such as Reserve Officers' Training Corps (ROTC) cadets, body composition is used not only as a predictor of fitness but for additional purposes such as qualification for enlistment, load carriage, and duty fulfillment. Body mass index (BMI) is the initial measurement recorded and is considered a representation of health and physical performance capabilities. Personnel exceeding threshold values of body weight based upon their height measurement are typically further evaluated using a circumference-based method that predicts the cadets' percent body fat. Military personnel who fail to meet these body composition standards may be penalized by being denied specific positions or promotions or risk being relieved from all military duties. In order to differentiate and accurately assess the components that constitute body composition, other methods of measuring body composition that provide greater accuracy should be explored. The purpose of this study was to compare multiple body composition methods, including the military's method of circumference-based measurement, in order to identify a suitable method for Air Force ROTC programs.

MATERIALS AND METHODS

Participants were recruited from an Air Force ROTC Detachment at a large university in the Midwest United States. Anthropometric (height and weight) and body composition measurements (air displacement plethysmography [ADP], bioelectrical impedance analysis, skinfolds, and circumferences) were collected for each participant. A repeated-measure analysis of variance was used to compare body composition measurement methods. A Bonferroni adjustment was utilized for multiple comparisons. BMI and circumference results were displayed as a percentage of compliance according to Air Force Instruction guidelines. The university institutional review board approval was established to ensure that the design of this study protected the rights of the participants.

RESULTS

Twenty-four (21 males and 3 females) participants completed the study. A significant difference between skinfolds and bioelectrical impedance analysis occurred (P = .025). There were no other significant differences identified between other methods of body composition. Using the BMI and circumference compliant/non-compliant scale listed in the Air Force Instruction guidelines, a greater number of cadets fell into the non-compliant category according to BMI (n = 7) versus circumferences (n = 1). The circumference-based method underestimated body fat compared to the "gold standard" ADP.

CONCLUSIONS

The findings from this investigation suggest that the circumference-based method can appropriately provide accurate body composition results among Air Force ROTC cadets. Results also determined that the military's circumference-based method underestimated body fat compared to the "gold standard" ADP. Although circumference-based measurements might be efficient for use in larger populations, Air Force ROTC programs should evaluate other methods of measuring body composition to best fit the needs of individual cadets. Further research should be conducted to identify body composition methods that are easy to implement and provide accurate results at the individual level.

Physical performance and body composition reference values for modern US Marine Corps women

Women's roles in the US military have progressively changed over the past several decades. Previously women were barred from combat roles. Recent change in policy allow women into combat roles in the Marine Corps, and this has led to women being trained for combat specialties.

Objectives

This observational cross-sectional study describes body composition and performance values for modern Marine Corps women.

Methods

Volunteers were 736 Marine women who were assessed for body composition and physical performance; (age 29.5±7.3 (18-56) years; height 163.6±6.8 (131.0-186.1) cm; body mass 68.3±9.2 (42.0-105.3) kg; years in the military 8.9±6.8 (0.5-37) years-in-service). Body composition measures were obtained using dual-energy X-ray absorptiometry and single-frequency bioelectrical impedance analyses. Performance measures were obtained from official physical and combat fitness test scores (PFT; CFT) as well as from data on measured countermovement jumps (CMJ) on a calibrated force platform.

Results

Mean body composition metrics for Marine women were: 47.5±5.7 fat free mass (FFM) (kg), 30.1%±6.4% body fat (%BF), 2.6±0.3 bone mineral content (kg), and 25.5±2.8 body mass index (kg/m2); performance metrics included 43.4±3.2 maximal oxygen uptake (VO2max; mL.kg.min), 22.4±7.1 CMJ height (cm) and 2575±565.2 CMJ peak power (W). Data showed strong correlations (r) (≥0.70) between PFT and VO2max scores (0.75), and moderate correlations (≥0.50) between CFT and VO2max scores (0.57), CFT and PFT scores (0.60), FFM and CMJ peak power (W) (0.68), and %BF to VO2max (-0.52), PFT (-0.54), CMJ-Ht (-0.52) and CMJ relative power (W/kg) (-0.54).

Conclusion

Modern Marine women are both lean and physically high performing. Body composition is a poor predictor of general physical performance.

The Impact of a 10-Week Military Training Course on Saudi Medical Recruits' Fitness and Physical Activity Levels

Background In preparation for military service, new recruits undergo a physical transformation. We aimed to determine the fitness outcomes and self-reported activity levels of Saudi medical recruits after a 10-week initial military training course (IMTC). Methods The cohort comprised 104 recruits aged 25-29 years. Anthropometric variables, including height, body mass index (BMI), body weight (BW), percent body fat (%BF), lean body mass (LBM), waist circumference (WC), and waist-to-height ratio (WtHR), were assessed pre-IMTC and post-IMTC. Physical fitness assessments, including a one-minute sit-up test, push-up test, Cooper's 12-minute run/walk test, and relative maximal oxygen consumption (VO2 max), were also evaluated. The International Physical Activity Questionnaire (IPAQ) was used to assess self-reported physical activity. Results We found a significant decrease in anthropometric variables following the course, including BW (P = 0.01), BMI (P = 0.01), %BF (P = 0.002), LBM (P = 0.01), WC (P = 0.005), and WtHR (P = 0.003). They also showed significant improvements in the push-up test (P = 0.001), one-minute sit-up test (P = 0.001), 12-minute test (P = 0.001), and relative VO2 max (P = 0.001). The comparison of pre-IPAQ with post-IPAQ demonstrated a percentage improvement in walking activity (15%-82%) and vigorous physical activity (17%-49%) after joining the IMTC. Conclusions These findings demonstrate that Saudi medical recruits who partake in the IMTC can attain significant improvements in their body composition, physical fitness, and physical activity levels.

US Army basic combat training alters the relationship between body mass index and per cent body fat

INTRODUCTION/BACKGROUND

As a proxy for adiposity, body mass index (BMI) provides a practical public health metric to counter obesity-related disease trends. On an individual basis, BMI cannot distinguish fat and lean components of body composition. Further, the relationship between BMI and body composition may be altered in response to physical training. We investigated this dynamic relationship by examining the effect of US Army basic combat training (BCT) on the association between BMI and per cent body fat (%BF).

METHODS

BMI and %BF were measured at the beginning (week 1) and end (week 9) of BCT in female (n=504) and male (n=965) trainees. Height and weight were obtained for BMI, and body composition was obtained by dual X-ray absorptiometry. Sensitivity and specificity of BMI-based classification were determined at two BMI thresholds (25 kg/m2 and 27.5 kg/m2).

RESULTS

A progressive age-related increase in fat-free mass index (FFMI) was observed, with an inflection point at age 21 years. In soldiers aged 21+, BMI of 25.0 kg/m2 predicted 33% and 29% BF in women and 23% and 20% BF in men and BMI of 27.5 kg/m2 predicted 35% and 31% BF in women and 26% and 22% BF in men, at the start and end of BCT, respectively. Sensitivity and specificity of BMI-based classification of %BF were poor. Soldiers below BMI of 20 kg/m2 had normal instead of markedly reduced %BF, reflecting especially low FFMI.

CONCLUSIONS

BCT alters the BMI-%BF relationship, with lower %BF at a given BMI by the end of BCT compared with the beginning, highlighting the unreliability of BMI to try to estimate body composition. The specific BMI threshold of 25.0 kg/m2, defined as 'overweight', is an out-of-date metric for health and performance outcomes. To the extent that %BF reflects physical readiness, these data provide evidence of a fit and capable military force at BMI greater than 25.0 kg/m2.

Exploring Influences of Eating Behaviors Among Emerging Adults in the Military

OBJECTIVE

Identify factors influencing eating behaviors among emerging adults in the military.

DESIGN

Focused ethnography using interviews, observations, and artifacts for data.

SETTING

Three US Naval installations.

PARTICIPANTS

Thirty-two active-duty Sailors aged 18-25 years.

ANALYSIS

Qualitative data were organized in NVivo and analyzed sequentially to categorize culturally relevant domains and themes using a social ecological model (SEM). Descriptive statistics were used to describe questionnaire data in SPSS (version 27.0, IBM, 2020).

RESULTS

Leaders encouraged healthy eating through policies and messages, but cultural contradictions and environmental barriers undermined Sailors' efforts to eat healthily. Stress and resource constraints (intrapersonal), peer pressure (social), unhealthy food environments and lack of access to food preparation (environmental), and eating on the go because of mission-first norms (cultural) promoted unhealthy eating behaviors. Nutrition and culinary literacy (intrapersonal); peer support and leadership engagement (social); access to healthy, convenient, and low-cost foods (environmental); and indoctrination to healthy eating during recruit training (cultural) positively influenced eating behaviors.

CONCLUSION AND IMPLICATIONS

The eating behaviors of service members are influenced by many modifiable factors. Targeted education, leadership engagement, and policies that make nutritious foods easily accessible, appealing, and preferred are needed.

Decreased Percent Body Fat but Not Body Mass is Associated with Better Performance on Combat Fitness Test in Male and Female Marines

ABSTRACT

Pletcher, ER, Lovalekar, M, Coleman, LC, Beals, K, Nindl, BC, and Allison, KF. Decreased percent body fat but not body mass is associated with better performance on the Marine Corps Combat Fitness Test. J Strength Cond Res 37(4): 887-893, 2023-The military uses a variety of physical fitness tests to assess physical readiness. The Marine Corps designed the Combat Fitness Test (CFT) to emphasize functional fitness related to operational demands. The purpose of this study was to investigate the association between body mass (BM), fat free mass (FFM), and percent body fat (BF%) measured via air displacement plethysmography with CFT performance in male and female marines. Two-hundred 10 male (22.4 ± 2.6 years) and 84 female (22.6 ± 2.8 years) marines were grouped into quintiles according to BM (in kilograms), FFM (in kilograms), and BF%. Kruskal-Wallis test or 1-way analysis of variance were used to determine if significant differences in CFT total and component scores existed between the groups of subjects classified into quintiles of BM, FFM, and BF%. No significant differences in CFT scores were observed between BM quintile in either men or women. No significant differences in CFT scores were observed between FFM quintiles in men. Total CFT score ( p = 0.002), movement to contact (MTC; p = 0.014), maneuver under fire (MANUF; p = 0.008), and ammunition lift (AL; p = 0.014) were all significantly different among FFM quintiles in women. Total CFT score ( p = 0.007), MTC ( p = 0.001), and MANUF ( p = 0.022) were significantly different among BF% quintiles in men. Total CFT score ( p = 0.008), MTC ( p = 0.033), and AL ( p = 0.016) were significantly different among BF% quintiles in women. Male and female marines in the quintile with lowest BF% had better CFT scores than those in higher quintiles. Targeted physical training and nutrition considerations to optimize BF% may help improve military task performance.

The Influence of Previous Lifestyle on Occupational Physical Fitness in the Context of Military Service

The Estonian Defense Forces are the basis of military service, mandatory for all male citizens of the Republic of Estonia who are at least 17 years old. The physical load in military service, especially in the first stage, is significantly greater than for men in everyday life. Therefore, it is important to know if health promotion in civilian life adequately prepares young people for military service and to what extent pre-military health behaviors affect physical performance during service. The purpose of this work was to examine conscripts' physical fitness at different stages of military service and its relationships with previous lifestyle. Soldiers' physical fitness was estimated three times during military service using three tests: sit-ups, push-ups and 2-mile run. Lifestyle and socio-economic background data was collected by a web-based questionnaire (n = 235). Linear regression analysis was performed using Army Physical Fitness Test (APFT) scores as dependent variables and questionnaire data as independent variables. The socio-economic background variables had no effect on physical fitness scores throughout the training period (p > 0.05). Young men that were physically more active daily, did sports, had healthier diet and did not smoke before entering military service showed better physical fitness test results throughout the period of service (p < 0.05). The effect of participation in sports was evident, as the conscripts with previous sports experiences demonstrated higher fitness tests scores (p < 0.01). These findings show that health promotion initiatives or programs for promoting physical activity and healthy diet, and preventing obesity and tobacco use, can also have a positive effect on the physical performance of young men during military service.

Body shape and performance on the US Army Combat Fitness Test: Insights from a 3D body image scanner

OBJECTIVE

To identify relationships between body shape, body composition, sex and performance on the new US Army Combat Fitness Test (ACFT).

METHODS

Two hundred and thirty-nine United States Military Academy cadets took the ACFT between February and April of 2021. The cadets were imaged with a Styku 3D scanner that measured circumferences at 20 locations on the body. A correlation analysis was conducted between body site measurements and ACFT event performance and evaluated using Pearson correlation coefficients and p-values. A k-means cluster analysis was performed over the circumference data and ACFT performance were evaluated between clusters using t-tests with a Holm-Bonferroni correction.

RESULTS

The cluster analysis resulted in 5 groups: 1. "V" shaped males, 2. larger males, 3. inverted "V" shaped males and females, 4. "V" shaped smaller males and females, and 5. smallest males and females. ACFT performance was the highest in Clusters 1 and 2 on all events except the 2-mile run. Clusters 3 and 4 had no statistically significant differences in performance but both clusters performed better than Cluster 5.

CONCLUSIONS

The association between ACFT performance and body shape is more detailed and informative than considering performance solely by sex (males and females). These associations may provide novel ways to design training programs from baseline shape measurements.

Military Body Composition Standards and Physical Performance: Historical Perspectives and Future Directions

ABSTRACT

Harty, PS, Friedl, KE, Nindl, BC, Harry, JR, Vellers, HL, and Tinsley, GM. Military body composition standards and physical performance: historical perspectives and future directions. J Strength Cond Res 36(12): 3551-3561, 2022-US military physique and body composition standards have been formally used for more than 100 years. These metrics promote appropriate physical fitness, trim appearance, and long-term health habits in soldiers, although many specific aspects of these standards have evolved as evidence-based changes have emerged. Body composition variables have been shown to be related to many physical performance outcomes including aerobic capacity, muscular endurance, strength and power production, and specialized occupational tasks involving heavy lifting and load carriage. Although all these attributes are relevant, individuals seeking to improve military performance should consider emphasizing strength, hypertrophy, and power production as primary training goals, as these traits appear vital to success in the new Army Combat Fitness Test introduced in 2020. This fundamental change in physical training may require an adjustment in body composition standards and methods of measurement as physique changes in modern male and female soldiers. Current research in the field of digital anthropometry (i.e., 3-D body scanning) has the potential to dramatically improve performance prediction algorithms and potentially could be used to inform training interventions. Similarly, height-adjusted body composition metrics such as fat-free mass index might serve to identify normal weight personnel with inadequate muscle mass, allowing for effective targeted nutritional and training interventions. This review provides an overview of the origin and evolution of current US military body composition standards in relation to military physical readiness, summarizes current evidence relating body composition parameters to aspects of physical performance, and discusses issues relevant to the emerging modern male and female warrior.

Anthropometrics and body composition predict performance during a simulated direct-fire engagement

This study determined anthropometric and body composition predictors of performance during a simulated direct-fire engagement. Healthy subjects (N = 33, age = 25.7 ± 7.0 yr) underwent anthropometric and body composition assessments before completing a simulated direct-fire engagement - consisting of marksmanship with cognitive workload assessment and a fire-and-move drill (16 × 6-m sprints) while wearing combat load. Susceptibility to enemy fire was modelled on sprint duration. Partial correlations and multiple linear regressions established the relationships between predictors and performance outcomes, controlling for age and sex. Significance was p ≤ 0.05. Higher percent body fat, fat mass, fight load index predicted greater susceptibility to enemy fire (r = 0.40 to 0.42) and lower cognitive performance (r= -0.45 to -0.49). Higher BMI also predicted lower cognitive performance (r= -0.49). Shorter stature/hand length predicted higher marksmanship accuracy (r= -0.40), while higher fat-free mass/fat-free mass index predicted slower reaction times (r = 0.36-0.41). These data suggest anthropometric and body composition measures modulate combat effectiveness and reinforce body composition standards in military organisations. Practitioner summary: This study identified field-expedient anthropometric and body composition predictors of a simulated direct-fire engagement that evaluated survivability (i.e. susceptibility to enemy fire) and lethality (i.e. marksmanship, cognitive performance) outcomes. Our findings suggest that anthropometric and body composition measures may play a role in soldier survivability and lethality during simulated direct-fire engagements.

The dietary inflammatory index is associated with aerobic performance and anthropometric measures of marines

Evidence propose that dietary intake affects physical performance and body composition. The present study aimed to determine the relationship between dietary inflammatory index (DII) with physical function and anthropometric indices in the marine. This cross-sectional study was performed on 300 males aged 18 to 45 years serving in the Navy. A general questionnaire was used to collect demographic data of participants. Also, the anthropometric indices (height, weight, waist circumference, and hip circumference) were measured to calculate a body shape index (ABSI), abdominal volume index (AVI), body adiposity index (BAI), and conicity as new anthropometric indices. Moreover, the 12-min Cooper, sit up, pull up, and push up were used to assess physical performance. Food intake over the past year was assessed using a 147-item food frequency questionnaire, and then the DII score was calculated for each subject. Aerobic performance was assessed using the Cooper test. Also, the repetitions of sit up, pull up and push up in 1 minute were recorded to assess muscular endurance. The present study showed that the increase in DII is directly related to body mass index (BMI) (P=0.04), body fat percentage (P=0.03), and BAI (P=0.010) and inversely related to VO2max (P=0.001). However, after adjusting for the effect of energy intake in regression model, only the association between DII and VO2max was statistically significant (β=-1.69, standard error=0.67, P=0.01). The increase in the dietary inflammatory potential is associated to a higher BMI and body adiposity and a lower aerobic capacity in military personnel. However, the observed relationship between DII and anthropometric indices seems to be influenced by the energy intake. Further well-designed studies with a prospective method are warranted.

Baseline Characteristics and Their Associations with Body Composition of Active-Duty Service Members Enrolling in a Randomized Controlled Trial of a Weight Management Program

INTRODUCTION

Increasing rates of overweight and obesity among military service members (SMs) necessitate the implementation of weight management interventions. Evidence for the effectiveness of military weight management interventions is mixed. Effectiveness may be impacted by individual sociodemographic, psychiatric, psychological, and behavioral factors. Baseline data from SMs who were overweight/obese or at risk of failing body composition or physical fitness tests and enrolling in a weight management randomized controlled trial were used to examine (1) individual characteristics of this sample as a whole and by gender and (2) relationships between those characteristics and body composition metrics that are targeted by military weight management interventions. Understanding these relationships may inform intervention approaches.

MATERIALS AND METHODS

Active duty SMs (N = 178) who enrolled in a randomized clinical trial of the Navy's weight management program "ShipShape" at a large military hospital provided data at their baseline visit. Because of gender differences in average body fat percentage (BF%) and underrepresentation of women SMs in research, independent samples t-tests and chi-square analyses were used to examine differences between male and female SMs across study variables. Multiple regression analyses were used to examine relationships of sociodemographic, psychiatric, psychological, and behavioral variables with body composition metrics, including weight, body mass index (BMI), BF%, and waist circumference (WC).

RESULTS

Participants (61% female; Mage = 29.66 ± 6.92 years; 59.60% White) had an average BMI in the "obese" range (MBMI = 33.1 ± 3.9 kg/m2). Female participants had significantly higher BF% and significantly lower weight and WC than male participants. Compared to male participants, females reported significantly higher rates of pain and headache diagnoses, lifetime diagnosis of an anxiety disorder, lifetime treatment for a mental health concern, lifetime experiences of sexual trauma/harassment and military sexual trauma, and higher current anxiety and post-traumatic stress disorder symptoms. Across all SMs, body composition metrics were significantly associated with several demographic variables, including gender, age, marital status, Asian race, and Black race. Higher weight-related stigma was significantly associated with higher weight, BMI, BF%, and WC. Additionally, more emotional eating was significantly associated with higher BF%, and higher weight-loss confidence was significantly associated with higher BMI. Sociodemographic, psychiatric, psychological, and behavioral variables predicted the greatest variance in BF% compared to other body composition metrics evaluated.

CONCLUSIONS

Participants in this study were more likely to be female, relatively young members of the Navy with overweight/obesity, who endorsed pain-related medical conditions, probable mental health conditions, and traumatic experiences at relatively high rates. Despite high endorsement of anxiety, depression, and post-traumatic stress disorder symptoms in this group, only weight-related stigma consistently emerged as significantly associated with body composition metrics. Regression results varied by body composition metric, with the most variance explained in BF%, suggesting that BF% may relate most strongly to sociodemographic, psychiatric, psychological, and behavioral variables associated with weight management. These results highlight the need for weight management programs that address weight-related stigma and mental health concerns of SMs to maximize the effectiveness of intervention efforts.

Body Composition of Female Air Force Personnel: A Comparative Study of Aircrew, Airplane, and Helicopter Pilots

This research aimed to analyze the body composition (BC) of different groups of women aircrew units in the Spanish Air Forces for a better understanding and improvement of their operability. Specifically, 184 female aircrew members were analyzed and classified into specialties (38 airplane pilots, age: 32.8 ± 10.8; 26 helicopter pilots, age: 32.0 ± 9.18; and 120 transport aircrew, age: 36.9 ± 8.18). The women’s BC was analyzed with an InBody720 bioimpedance device previously used in the military population. There were differences in the BC among specialties, although there were similarities between airplane and helicopter pilots. Airplane (24.0% ± 10.4%) and helicopter pilots (22.6 ± 6.32%) had a smaller percentage of body fat mass than transport aircrew (26.3 ± 7.51%), but there was uniformity among groups in skeletal muscle mass and soft lean mass. We found no differences in body water among specialties. Differences in BCs were previously reported for men in the air force, and these results in women showed similarities for different job entry requirements, different training needs, and different occupational behaviors among units in the Air Force. These results help to deepen the previous knowledge of women’s BC standards in military units. Although pilots are primarily responsible for the aircraft, healthy habits should be encouraged to keep fit and improve the performance of all aircrew members both in flight and when they are deployed.

Association of deployment with maintenance of healthy weight among active duty service members in the Millennium Cohort Study

Objective

Understanding body size in relation to deployment readiness can inform Department of Defense fitness policies. This study examined longitudinal associations between deployment and changes in body mass index (BMI) among active duty service members.

Methods

Service branch-specific changes in BMI post-deployment were examined using logistic regression models among active duty Millennium Cohort Study participants without obesity at baseline (n = 22,995). BMI was categorized using self-reported height and weight as healthy weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30 kg/m2). Number of deployments between baseline and follow-up and initial deployment lengths (in months, using service branch-specific deployment times) were examined.

Results

Among the pooled population and specifically Army and Marine Corps service members without obesity, those with longer deployments were significantly less likely to maintain a non-obese BMI than those deploying for shorter lengths. Each additional deployment increased the likelihood of maintaining a non-obese BMI post-deployment for personnel in the Army, Marine Corps, and within the pooled population.

Conclusions

Multiple deployments may support healthy weight maintenance; longer deployments may adversely impact weight maintenance. Future research should determine modifiable behaviors related to weight gain post-deployment to inform fitness policies designed to optimize service member readiness and deployability.

Body Composition Symmetry in Aircraft Pilots

The purpose of this study was to analyze the body composition symmetry in upper and lower body segments of aircrafts pilots. To reach the study aim, body composition in upper and lower body segments of 206 male aircraft pilots of the Spanish Army (23.1 ± 6.87 years) and 105 civilians (24.0 ± 6.29 years) were evaluated by a bioimpedance analyser (InBody 720, Biospace Co. Ltd., Seoul, Korea). Aircraft pilots presented a tendency to dysmetria in upper and lower body segments, showing fitter values in the protagonist side when performing flight functions. Dysmetria could be detrimental during flight manoeuvres and produce injuries in aircraft pilots. It would be recommended to design specific training protocols to improve this imbalance.

The interactions between interleukin-1 family genes: IL1A, IL1B, IL1RN, and obesity parameters

Background

Obesity has been recognized as a worldwide growing problem, producing many pathologies including the promotion of “proinflammatory state.” The etiology of human obesity is still only partially understood; however, the genetic background has been proved. Its nature is complex, and currently, it appears that the combined effects of the interactions among multiple genes should receive more attention. Due to the fact that obesity promotes proinflammatory conditions, in this study, we investigated the genetic polymorphism of IL-1 family genes in healthy people with normal and elevated body mass index (BMI) and fat %.

Results

The single-nucleotide polymorphisms (SNPs) within the IL1A -889C > T (rs1800587), IL1B + 3954 T > C (rs1143634), and IL1RN -87G > A (rs2234677) genes alone were associated neither with BMI nor fat % values in tested group. The associations between SNP–SNP interaction and BMI for the IL1B × IL1RN interactions were significant for dominant model (p = 0.02) and codominant model (p = 0.03). The same SNP-SNP interaction (IL1B × IL1RN) was associated also with fat % for codominant (p = 0.01) and recessive (p = 0.002) models.

Conclusions

This study further confirmed that IL-1 family genes are involved in genetic background of obesity. It has been shown that interaction IL1B × IL1RN was associated with both BMI and fat % with rare T allele protecting form higher values. Thus, even if certain polymorphisms in single genes of IL-1 family cannot be defined as related to obesity in examined population, the genetic interrelationships should be analyzed.

Effect of Physical Training on Body Composition in Brazilian Military

The military are selected on the basis of physical standards and are regularly involved in strong physical activities, also related to particular sports training. The aims of the study were to analyze the effect of a 7-month military training program on body composition variables and the suitability of specific ‘bioelectrical impedance vector analysis’ (spBIVA), compared to DXA, to detect the changes in body composition. A sample of 270 male Brazilian cadets (19.1 ± 1.1 years), composed of a group practicing military physical training routine only (MT = 155) and a group involved in a specific sport training (SMT = 115), were measured by body composition assessments (evaluated by means of DXA and spBIVA) at the beginning and the end of the military routine year. The effect of training on body composition was similar in SMT and MT groups, with an increase in LST. DXA and spBIVA were correlated, with specific resistance (Rsp) and reactance (Xcsp) positively related to fat mass (FM), FM%, LST, and lean soft tissue index (LSTI), and phase angle positively related to LST and LSTI. Body composition variations due to physical training were recognized by spBIVA: the increase in muscle mass was indicated by the phase angle and Xcsp increase, and the stability of FM% was consistent with the unchanged values of Rsp. Military training produced an increase in muscle mass, but no change in FM%, independently of the sample characteristics at baseline and the practice of additional sports. SpBIVA is a suitable technique for the assessment of body composition in military people.

Body mass index and aerobic capacity: The key variables for good performance in soldiers

Body composition, leg power and aerobic capacity have been shown to be related to performance, although their combined influence in a training task under load carriage in soldiers is still unknown. In this study, the influence of aerobic capacity, body composition and leg strength on performance during an obstacle test with and without combat equipment carriage was analysed. Forty males belonging to the Spanish Army participated in this study. The time needed to complete an obstacle course with and without load, aerobic capacity (20-m shuttle run test), leg power (squat jumps) and body composition variables (body mass index [BMI], fat mass and lean mass) were tested to determine the best predictors of performance. The results indicated that the best predictors of obstacle course performance with and without load carriage are VO_2max and BMI. The jump height was not a significant factor in the model. In conclusion, BMI and VO_2max are predictors of the obstacle test time with and without load carriage, so it is recommended that both variables are included as criteria for enrolment in the military army to guarantee army members exhibit the highest obstacle course performance possible. HighlightThe VO_2max and BMI are the best predictors of an obstacle course performance with/without load carriage.The jump height was not a significant performance factor.The VO_2max and BMI are recommended as enrolment criteria for military army.

Effects of modern military backpack loads on walking speed and cardiometabolic responses of US Army Soldiers

INTRODUCTION

Military leaders must understand how modern military equipment loads affect trade-offs between movement speed and physiological strain to optimize pacing strategies.

PURPOSE

To evaluate the effects of load carried in a recently developed military backpack on the walking speed and cardiometabolic responses of dismounted warfighters.

METHODS

Fifteen soldiers (1 woman, 14 men; age, 22 ± 2 years; height, 173 ± 7 cm; body mass (BM), 73 ± 10 kg) completed incremental walking tests with four external load conditions (0, 22, 44, or 66% BM) using the US Army's newest backpack: the Modular Lightweight Load-Carrying Equipment 4000 (MOLLE 4000). Oxygen uptake (V̇O₂) and heart rate (HR) were evaluated relative to maximal values (V̇O_2max and HR_max respectively). Testing ceased when participants completed the highest tested speed (1.97 m s^-1), exceeded a respiratory exchange ratio (RER) of 1.00, or reached volitional exhaustion.

RESULTS

Peak speed significantly decreased (p < 0.03) with successively heavier loads (0% BM, 1.95 ± 0.06 m s^-1; 22% BM, 1.87 ± 0.10 m s^-1; 44% BM, 1.69 ± 0.13 m s^-1; 66% BM, 1.48 ± 0.13 m s^-1). Peak V̇O₂ was significantly lower (p < 0.01) with 0% BM (47 ± 5% V̇O_2max) than each load (22% BM, 58 ± 8% V̇O_2max; 44% BM, 63 ± 10% V̇O_2max; 66% BM, 61 ± 11% V̇O_2max). Peak HR was significantly lower (p < 0.01) with 0% BM (71 ± 5% HR_max) versus each load (22% BM, 83 ± 6% HR_max; 44% BM, 87 ± 6% HR_max; 66% BM, 88 ± 6% HR_max).

CONCLUSION

Overburdened warfighters suffer severe impairments in walking speed even when carrying recently developed military load carriage equipment. Our results suggest that the relative work intensity of heavy load carriage may be better described when expressed relative to HR_max versus V̇O_2max.

Academy of Nutrition and Dietetics: Revised 2021 Standards of Practice and Standards of Professional Performance for Registered Dietitian Nutritionists (Competent, Proficient, and Expert) in Sports and Human Performance Nutrition

Nutrition in sports and human performance incorporates knowledge of the intersection of human physiology and nutrition. Registered dietitian nutritionist (RDN) practitioners in sports and human performance focus on nutrition care that is specific to the individual and their sport/occupational requirements. The Dietitians in Sports, Cardiovascular and Wellness Dietetic Practice Group, along with the Academy of Nutrition and Dietetics Quality Management Committee, have updated the Standards of Practice (SOP) and Standards of Professional Performance (SOPP) for RDNs working in sports and human performance. The SOP and SOPP for RDNs in Sports and Human Performance Nutrition provide indicators that describe three levels of practice: competent, proficient, and expert. The SOP uses the Nutrition Care Process and clinical workflow elements for delivering care to athletic/professional populations. The SOPP describes the following six domains that focus on professional performance: Quality in Practice, Competence and Accountability, Provision of Services, Application of Research, Communication and Application of Knowledge, and Utilization and Management of Resources. Specific indicators outlined in the SOP and SOPP depict how these standards apply to practice. The SOP and SOPP are complementary resources for RDNs and are intended to be used as a self-evaluation tool for assuring competent practice in sports and human performance and for determining potential education and training needs for advancement to a higher practice level in a variety of settings.

Circumference Method Estimates Percent Body Fat in Male US Service Members with Lower Limb Loss

BACKGROUND

The Department of Defense circumference method (CM) is used to estimate percent body fat (%BF) in evaluation of health, physical fitness, appearance, and military readiness; however, the CM has not been validated in individuals with lower limb loss.

OBJECTIVE

To evaluate the agreement between CM and dual-energy X-ray absorptiometry (DXA) for measuring %BF in individuals with lower limb loss.

DESIGN

This study is part of a larger cross-sectional comparison study, and this analysis was included as a secondary objective. Two methods of measuring %BF included CM and DXA, with DXA as the reference standard for this study.

PARTICIPANTS/SETTING

This study was conducted at Walter Reed Army Medical Center. Data were collected from summer 2010 to summer 2011. One hundred individuals, 50 with and 50 without lower limb loss, were screened for this study; three individuals with limb loss and two without limb loss had incomplete data, and one individual (female, without limb loss) lacked a comparison participant. All participants were recruited from a military medical center, and data were collected in a clinic research laboratory.

MAIN OUTCOME MEASURES

Measurements of %BF were compared between methods for each group.

STATISTICAL ANALYSES PERFORMED

Measurements of %BF were compared using paired t-tests and intraclass correlation coefficient. Agreement and bias were assessed with Bland-Altman analysis. Receiver operating characteristic analysis was used to determine the diagnostic accuracy of the CM to identify participants with %BF levels in the obese category (≥25%).

RESULTS

A statistically significant difference was found between %BF methods in the group with limb loss (1.7%; P = 0.001) and the group without limb loss (1.4%; P = 0.005), with DXA consistently higher than CM. However, the intraclass correlation coefficient estimates for the agreement between %BF by CM and DXA were 0.848 (95% confidence interval [CI]: 0.683-0.922; P < 0.001) and 0.828 (CI: 0.679-0.906; P < 0.001), for the groups with and without limb loss, respectively, suggesting that CM has good to near excellent agreement with DXA for estimating %BF in these groups. Receiver operating characteristic analysis indicated that the area under the curve supported predictive ability to detect obesity-based %BF in males with and without limb loss.

CONCLUSIONS

Although a statistically significant difference was found between methods for individuals with limb loss, there was also good agreement between the methods, suggesting that CM may be a useful tool for estimating %BF in individuals with lower limb loss. The CM may be a useful and field expedient method for assessing %BF in a clinical setting when DXA is not available.

Body fatness in sedentary and active students with different body mass index

Study aim: Numerous data have indicated that body fat stores undergo complicated regulation by genetic and environmental factors, including physical activity. However, the majority of studies did not take into account this aspect of lifestyle in proposed body fat limits. In this context it seems that a more precise and reliable classification of body fat is provided by the American Council on Exercise (ACE), which distinguishes individuals not only with respect to sex but also activity level.

Material and methods: A total of 793 students (312 sedentary and 481 active) volunteered to participate in the study. Among sedentary participants 147 were male and 165 female. Among active subjects 206 were male and 275 were female. Active subjects were engaged in different modes of physical activity according to the study program. In all participants body mass index (BMI) was calculated. In participants with BMI 18.5–24.9 and BMI ≥ 25 body fat was determined using four skinfold measurements. Thereafter participants were classified according to the percentage of body fat using ranges for males and females provided by the American Council on Exercise (ACE) (essential fat, athletes, fitness, average and obese fatness).

Results: None of the sedentary and active males with BMI 18.5–24.9 had high (obese) fat. In contrast, in sedentary males with BMI ≥ 25 16.4% were obese vs. 1.8% of obese active ones. In sedentary females BMI from 18.5 to 24.9 did not exclude obesity, which was found in 16.9% of participants. In sedentary females with BMI ≥ 25 most of the subjects (97.1%) were obese. In contrast, in active females with BMI ≥ 25 a similar percentage of participants had average and obese fat (53.3% and 46.7, respectively).

Discussion: Our study clearly demonstrated that BMI as a simple measure of body composition provides false information concerning true adiposity in physically active male and female students. A similar BMI did not exclude marked differences in the percentage of body fat in sedentary and active students.

One size does not fit all. How universal standards for normal height can hide deprivation and create false paradoxes

Public health practitioners and social scientists frequently compare height against one-size-fits-all standards of human growth to assess well-being, deprivation, and disease risk. However, underlying differences in height can make some naturally tall populations appear well-off by universal standards, even though they live in severe states of deprivation. In this article, I describe the worldwide extent of these population differences in height and illustrate how using a universal yardstick to compare population height can create puzzling disparities (eg, between South Asia and sub-Saharan Africa) while also underestimating childhood stunting in specific world regions (eg, West Africa and Haiti). I conclude by discussing potential challenges of developing and implementing population-sensitive standards for assessing healthy development.

Body Mass Index and Measures of Body Fat for Defining Obesity and Underweight: A Cross-Sectional of Various Specialties in Montenegrin Army Soldiers

Background:

The body composition and physical fitness of members of the army is always a relevant topic for research, since the level of defense and security of people and material goods in a specific territory in many ways depends on the level of ability of the army. However, members of the armed forces are a heterogeneous group, typified by different abilities, characteristics, but also everyday needs, and the trend of changing body composition and reducing physical fitness is a current issue that has not bypassed this population either. Therefore, this study aimed to determine possible differences in body composition indicators that could appear between members of the Army of Montenegro of different military specialties.

Methods:

The sample of respondents included 240 Montenegrin male soldiers (32.5yr±9.5), who were measured at the sports dispensaries within the barracks of Montenegrin Army around the country in the spring of 2020, was classified into eight numerically equal subsamples according to their military specialty. The sample of variables included five anthropometric measures, which were necessary to calculate two derived body composition indicators: Body Mass Index (BMI) and Body Fat Percentage (FAT %). Using the one-way ANOVA and Post Hoc test with Taki’s model, the variables were analyzed.

Results:

It was determined that the body composition of Montenegrin soldiers shows a certain peculiarity compared to other national military corps, while there are differences in body composition indicators between members of the Montenegrin Army of different military specialties.

Conclusion:

This fact dramatically strengthens the issues of Montenegrin distinctive regarding body composition, both in general terms and in terms of distinctive within specific professional vocations.

Five-component model validation of reference, laboratory and field methods of body composition assessment

This study reports the validity of body fat percentage (BF%) estimates from several commonly employed techniques as compared with a five-component (5C) model criterion. Healthy adults (n 170) were assessed by dual-energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), multiple bioimpedance techniques and optical scanning. Output was also used to produce a criterion 5C model, multiple variants of three- and four-component models (3C; 4C) and anthropometry-based BF% estimates. Linear regression, Bland-Altman analysis and equivalence testing were performed alongside evaluation of the constant error (CE), total error (TE), se of the estimate (SEE) and coefficient of determination (R2). The major findings were (1) differences between 5C, 4C and 3C models utilising the same body volume (BV) and total body water (TBW) estimates are negligible (CE ≤ 0·2 %; SEE < 0·5 %; TE ≤ 0·5 %; R2 1·00; 95 % limits of agreement (LOA) ≤ 0·9 %); (2) moderate errors from alternate TBW or BV estimates in multi-component models were observed (CE ≤ 1·3 %; SEE ≤ 2·1 %; TE ≤ 2·2 %; R2 ≥ 0·95; 95 % LOA ≤ 4·2 %); (3) small differences between alternate DXA (i.e. tissue v. region) and ADP (i.e. Siri v. Brozek equations) estimates were observed, and both techniques generally performed well (CE < 3·0 %; SEE ≤ 2·3 %; TE ≤ 3·6 %; R2 ≥ 0·88; 95 % LOA ≤ 4·8 %); (4) bioimpedance technologies performed well but exhibited larger individual-level errors (CE < 1·0 %; SEE ≤ 3·1 %; TE ≤ 3·3 %; R2 ≥ 0·94; 95 % LOA ≤ 6·2 %) and (5) anthropometric equations generally performed poorly (CE 0·6- 5·7 %; SEE ≤ 5·1 %; TE ≤ 7·4 %; R2 ≥ 0·67; 95 % LOA ≤ 10·6 %). Collectively, the data presented in this manuscript can aid researchers and clinicians in selecting an appropriate body composition assessment method and understanding the associated errors when compared with a reference multi-component model.

Energy Deficiency in Soldiers: The Risk of the Athlete Triad and Relative Energy Deficiency in Sport Syndromes in the Military

Military personnel experience energy deficit (total energy expenditure higher than energy intake), particularly during combat training and field exercises where exercising energy expenditures are high and energy intake is reduced. Low energy availability (energy intake minus exercising energy expenditure expressed relative to fat free mass) impairs endocrine function and bone health, as recognized in female athletes as the Female Athlete Triad syndrome. More recently, the Relative Energy Deficiency in Sport (RED-S) syndrome encompasses broader health outcomes, physical and cognitive performance, non-athletes, and men. This review summarizes the evidence for the effect of low energy availability and energy deficiency in military training and operations on health and performance outcomes. Energy availability is difficult to measure in free-living individuals but doubly labeled water studies demonstrate high total energy expenditures during military training; studies that have concurrently measured energy intake, or measured body composition changes with DXA, suggest severe and/or prolonged energy deficits. Military training in energy deficit disturbs endocrine and metabolic function, menstrual function, bone health, immune function, gastrointestinal health, iron status, mood, and physical and cognitive performance. There are more data for men than women, and little evidence on the chronic effects of repeated exposures to energy deficit. Military training impairs indices of health and performance, indicative of the Triad and RED-S, but the multi-stressor environment makes it difficult to isolate the independent effects of energy deficiency. Studies supplementing with energy to attenuate the energy deficit suggest an independent effect of energy deficiency in the disturbances to metabolic, endocrine and immune function, and physical performance, but randomized controlled trials are lacking.

Body mass index and waist-to-hip ratio misclassification of overweight and obesity in Chinese military personnel

BACKGROUND

The rising prevalence of obesity in military personnel has raised great concerns. Previous studies suggest that body mass index (BMI)- and waist-to-hip ratio (WHR)-based obesity classifications in US military personnel and firefighters have high false negative and subsequently cause obesity misclassification.

OBJECTIVE

To determine whether BMI and WHR could reflect the fat mass of Chinese military personnel.

METHODS

Three hundred fifty-three male Chinese military personnel and 380 age-matched male adults were recruited. Obesity classification was defined by BMI, WHR, and body fat percentage (BFP).

RESULTS

Chinese military personnel had extremely low obesity rate determined by either BFP (0.3%) or BMI (0.6%). By combining overweight and obese individuals, BMI- and WHR-determined prevalence of overweight/obesity was 22.4% and 17.0% compared to BFP-based standard (4.0%) (P < 0.05). In reference to BFP, BMI and WHR have high false-positive rate compared to the control group. Further analysis showed that Chinese military personnel consisted of high percentage of BFP^lowBMI^high and/or BFP^lowWHR^high subpopulations. Eighty-one percent of BMI^high and 78.3% of WHR^high of them were BFP low.

CONCLUSIONS

Chinese military personnel has extremely low obesity rate. BMI and WHR have high false-positive rates in reference to BFP, which cannot accurately reflect the mass of adipose tissue and leads to obesity misclassification.

Body Mass Index Effect on Health Service Utilization Among Active Duty Male United States Army Soldiers

INTRODUCTION

Obesity and overweight, defined as body mass index (BMI) of 30.0 and above or 25.0-29.9, respectively, are of significant concern to the military population, due to their associated comorbidities and potential for impaired readiness. In 2016, the US Army reported a prevalence of 17.3% obesity and 52.9% overweight among soldiers, despite both physical demands of the job and Department of Defense (DoD) guidelines which recommend separation from service for those unable to meet body composition standards. This study examines the health service utilization of active duty, male Army soldiers in order to determine the prevalence of obesity and overweight and to estimate the effects of these conditions on readiness.

MATERIALS AND METHODS

This was a cross-sectional study utilizing fiscal year (FY) 2015 TRICARE claims and military treatment facility (MTF) encounter data obtained from the Military Health System Data Repository (MDR), for 467,732 US Army male Soldiers on active duty. We obtained basic demographic information (age, race, and rank) from the Defense Enrollment Eligibility Reporting System (DEERS). Next, we calculated BMI for this cohort by matching patients to their vital statistics of height and weight measurements. Finally, we obtained their health service utilization by querying and matching patients to their healthcare claims in 2015 by major diagnostic category.

FINDINGS

More than half (51.2%) of subjects had overweight, 28.9% had normal weight, 19.7% had obesity, and less than 1% had underweight. Soldiers with overweight and obesity were most common among the 25-34 years age range and enlisted ranks. Normal weight and underweight soldiers had a median of 7 healthcare visits in FY 2015, compared with 8 for soldiers with overweight and 12 for those with obesity. Soldiers with obesity, but not overweight, had a disproportionately greater number of healthcare encounters for diagnostic categories including musculoskeletal; mental health; ear, nose, and throat; and endocrine system. In contrast, soldiers with obesity had disproportionately fewer healthcare encounters for multiple significant trauma and for infectious and parasitic diseases.

CONCLUSIONS

More than 70% of soldiers had overweight or obesity in FY 2015, showing the highest prevalence yet measured for these conditions. Previous reports of lower prevalence may be due to the inclusion of circumference-based body fat assessments, which have been criticized for inaccuracy. In our study, disproportionately high health service use by soldiers with obesity suggests decreased readiness, as these soldiers may experience both poorer health and lose necessary training time due to increased provider visits. Proportional usage by soldiers with overweight suggests the protective effect of regular physical activity, though these soldiers should be monitored to ensure that they do not progress to obesity. Additional research should establish the burden of cost, absenteeism, and presenteeism of obesity on the MHS, as well as developing more appropriate field tests for body fat assessment and BMI standards to better support military readiness.

The effect of fish oil supplementation on the promotion and preservation of lean body mass, strength, and recovery from physiological stress in young, healthy adults: a systematic review

Context

Military personnel are subjected to physiologically stressful environments during combat and its associated training. Evidence suggests that fish oil–derived n-3 polyunsaturated fatty acids (FO n-3 PUFAs) may affect military personnel’s performance by promoting or preserving lean body mass, strength, and power, while enhancing recovery from training-associated muscle damage.

Objective

Following PRISMA guidelines, this systematic review assessed the evidence for FO n-3 PUFA supplementation across various military-relevant outcomes related to physical performance in healthy adult populations.

Data Sources

The PubMed, Embase, and the CINAHL databases were searched along with references lists of selected articles and reviews.

Data Extraction

Eighteen trials were assessed for bias, and descriptive data were extracted.

Data Analysis

Of the 18 studies included, 12 trials favored FO n-3 PUFA supplementation in ≥ 1 of the performance outcomes.

Conclusion

Overall, FO n-3 PUFA supplementation likely preserves strength and very likely enhances recovery from physiological stress in young, healthy adults. However, FO n-3 PUFAs’ role in promoting or preserving lean body mass or promoting strength is unclear and warrants additional investigation.

Systematic Review Registration

PROSPERO registration no. CRD42020152786.

Weight Perceptions and Weight Loss Attempts: Military Service Matters

INTRODUCTION

People who do not perceive themselves as overweight or obese are less likely to use weight loss treatments. However, little is known about weight perceptions and their association with weight loss attempts among people who have served in the military. They represent a special population with regard to weight perceptions as military personnel must meet strict weight standards to remain in military service.

MATERIALS AND METHODS

Using data from the U.S.-based 2013-2014 and 2015-2016 National Health and Nutrition Examination Surveys, we fit logistic regression models to determine whether people with overweight or obesity were: (1) more or less likely to underestimate their weight if they reported military service and (2) less likely to attempt weight loss if they underestimated their weight (stratifying by military status). Estimates were adjusted for sociodemographic factors, including objective weight class, gender, age, race/ethnicity, income ratio, comorbidities, and education. This work received exempt status from the Stanford University institutional review board.

RESULTS

Among 6,776 participants, those reporting military service had higher odds of underestimating their weight compared to those not reporting military service [OR (odds ratio): 1.44; 95% confidence interval (CI): 1.15, 1.79]. Underestimating weight was associated with lower odds of attempting weight loss among those reporting military service (OR: 0.20; CI: 0.11, 0.36) and those not reporting military service (OR: 0.27; CI: 0.22, 0.34).

CONCLUSIONS

This study offers the new finding that underestimating weight is more likely among people reporting military service compared to those not reporting military service. Findings are consistent with past work demonstrating that underestimating weight is associated with a lower likelihood of pursuing weight loss. To combat weight misperceptions, clinicians may need to spend additional time discussing weight-related perceptions and beliefs with patients. The present findings suggest such conversations may be especially important for people reporting military service. Future research should be designed to understand the effects of correcting weight misperceptions. This work would advance the science of weight management and offer ways to increase weight loss treatment engagement, prevent chronic conditions, and improve health outcomes, especially among people reporting military service.

Comparison of Anthropometric Measures in US Military Personnel in the Classification of Overweight and Obesity

OBJECTIVE

This study aimed to determine (1) the level of agreement between BMI, circumference-based equation (CBE) measures, waist circumference (WC), and bioelectrical impedance analysis (BIA) measures and (2) whether BMI, CBE measures, or WC alone or in combination adequately reflects adiposity in military personnel compared with BIA.

METHODS

BMI from measured height and weight (using military overweight cutoffs in men [BMI ≥ 27.5 kg/m² ] and World Health Organization overweight cutoffs [BMI ≥ 25.0 kg/m² ]), BMI body fat percentage (BF%), WC, CBE BF%, and BIA BF% were collected. Respondents (N = 389, 78% men) were categorized with normal fat versus overweight, obesity, or overfat. Levels of agreement and standard screening performance measures were compared between anthropometric measures and BIA.

RESULTS

World Health Organization BMI and BIA BF% classified the most men and women with overweight/obesity; WC with BMI (BMI + WC) and WC alone classified the fewest men and women with overweight/obesity. Levels of agreement were all statistically significant and highest for BMI (men: Cohen's κ = 0.711; women: Cohen's κ = 0.814) and lowest for WC and BMI + WC (all Cohen's κ ≤ 0.270). BMI + CBE performed best overall (sensitivity = 50.9%, false discovery rate = 5.4%).

CONCLUSIONS

Our findings support BMI + CBE as an easy-to-implement combination to assess adiposity in the military.

Relationship of Anthropometric Measures on Female Trainees' and Active Duty Soldiers' Performance of Common Soldiering Tasks

INTRODUCTION

This study compared the relationship between height (HT), body mass (BM), and body mass index (BMI) of female trainees and active duty female soldiers and their performance on simulated common soldiering tasks (CSTs) with high physical demands.

METHODS

Female trainees (n = 133) and soldiers (n = 229) completed the following CSTs: sandbag carry, move under fire, casualty drag, casualty evacuation, and road march. Quartiles were created among HT, BM, and BMI by which task performance was compared using ANOVAs with Tukey post hoc comparisons.

RESULTS

For both trainees and soldiers, HT, BM, and BMI were positively associated with improved road march, casualty drag, casualty evacuation, and sandbag carry performance. On the move under fire task, only soldier HT was positively associated with improved performance.

CONCLUSION

Female trainees and soldiers who are taller and heavier with a higher BMI may demonstrate better performance on CSTs required of all soldiers. In addition to task-specific training, performance of CSTs may be enhanced in tasks requiring strength and power by recruiting and retaining taller and heavier females with a higher BMIs. Allowances should be considered for soldiers and trainees who can successfully perform soldiering tasks with high physical demands despite less desirable anthropometric measurements.

A Multidimensional Approach to Assessing Anthropometric and Aerobic Fitness Profiles of Elite Brazilian Endurance Athletes and Military Personnel

INTRODUCTION

Military personnel must remain physically active to meet operational requirements. Military physical training not only provides the performance capabilities required for performing occupational tasks but also fosters the development of sport. Thus, Armed Forces across the world have historically invested in developing elite- and Olympic-level athletes. This study aimed to assess the anthropometric and physiological differences among groups of Brazilian military athletes (MA), non-military athletes (A), and military non-athletes (M).

MATERIALS AND METHODS

Seventy-five individuals participated in the study: 17 MA (23.7 ± 4.8 years), 27 A (24.7 ± 5.3 years), and 31 M (26.9 ± 3.3 years). MA and A individuals specialized in endurance sports, and had a mean weekly training volume of (100.0 ± 34.8 and 106.3 ± 40.5 Km; F = 0.894, p = 0.6), respectively. Anthropometric measures and maximal oxygen uptake (V̇O2máx) were assessed in all participants. Ergospirometry and anthropometry variables were analyzed with one-way analysis of variance (ANOVA) for independent measures. Comparisons of weekly training volume (km) and training experience (years) were performed only between the A and MA using the Student's t-test for independent samples. For a multidimensional approach, Partial least squares discriminant analysis (PLS-DA) was performed for all variables using the online tool MetaboAnalyst.

RESULTS

We found no differences in anthropometric and physiological profiles between A and MA, but significant differences between M and MA/A in body mass index (kg/m2) (BMI), body fat percentage, fat mass (kg), waist circumference (cm) (WC), somatotype, and V̇O2máx (mL min-1 kg-1).

CONCLUSION

In conclusion, military endurance athletes have similar anthropometric and physiological profiles to non-military athletes and superior levels to non-athlete military. These findings indicate that the Brazilian Armed Forces scouting system has been successful in identifying endurance athletic talent in line with their historic role of developing sport in Brazil.

Physical training over 6 months is associated with improved changes in phase angle, body composition, and blood glucose in healthy young males

OBJECTIVES

The aim of this study was to evaluate the association between phase angle, body composition, and blood glucose changes in healthy young males after 6 months of physical training.

METHODS

Volunteers, 98 healthy males (18.8 ± 0.5 years), had 6 months of progressive physical training (5 days a week, 90 minutes a day). Resistance, reactance, and phase angle were obtained by bioelectrical impedance analysis, body composition (fat mass, bone mineral content [BMC], and lean soft tissue [LST]) by dual-energy X-ray absorptiometry, and blood glucose by reflectance photometry. Measurements were made at rest and in a fasted state, both before and after the training period.

RESULTS

Phase angle, reactance, BMC, and LST significantly increased (0.6°, 3.8 Ω, 0.1 kg, and 1.9 kg, respectively; P < .01), whereas resistance and blood glucose decreased (-11.2 Ω and -4.1 mg/dL; P < .01). Changes in resistance and reactance explained those changes observed in LST (R2 = .26 and .16, respectively), but phase angle changes were not related to body composition and blood glucose alterations (P < .05).

CONCLUSIONS

A 6-month period of physical training was associated with positive changes in phase angle, body composition, and blood glucose in healthy young males, reinforcing the importance of maintaining a physically active lifestyle.

Accuracy of Bioelectrical Impedance Analysis in Estimated Longitudinal Fat-Free Mass Changes in Male Army Cadets

Introduction

Bioelectrical impedance analysis (BIA) is a practical and rapid method for making a longitudinal analysis of changes in body composition. However, most BIA validation studies have been performed in a clinical population and only at one moment, or point in time (cross-sectional study). The aim of this study is to investigate the accuracy of predictive equations based on BIA with regard to the changes in fat-free mass (FFM) in Brazilian male army cadets after 7 mo of military training. The values used were determined using dual-energy X-ray absorptiometry (DXA) as a reference method.

Materials and Methods

The study included 310 male Brazilian Army cadets (aged 17-24 yr). FFM was measured using eight general predictive BIA equations, with one equation specifically applied to this population sample, and the values were compared with results obtained using DXA. The student's t-test, adjusted coefficient of determination (R2), standard error of estimation (SEE), Lin's approach, and the Bland-Altman test were used to determine the accuracy of the predictive BIA equations used to estimate FFM in this population and between the two moments (pre- and post-moment).

Results

The FFM measured using the nine predictive BIA equations, and determined using DXA at the post-moment, showed a significant increase when compared with the pre-moment (p < 0.05). All nine predictive BIA equations were able to detect FFM changes in the army cadets between the two moments in a very similar way to the reference method (DXA). However, only the one BIA equation specific to this population showed no significant differences in the FFM estimation between DXA at pre- and post-moment of military routine. All predictive BIA equations showed large limits of agreement using the Bland-Altman approach.

Conclusion

The eight general predictive BIA equations used in this study were not found to be valid for analyzing the FFM changes in the Brazilian male army cadets, after a period of approximately 7 mo of military training. Although the BIA equation specific to this population is dependent on the amount of FFM, it appears to be a good alternative to DXA for assessing FFM in Brazilian male army cadets.

Army Body Composition Program Study Results Concerning: Enrollees Are More Over Fat Than Expected

INTRODUCTION

Whether implementation of the Army Body Composition Program (ABCP) is meeting readiness objectives is unknown.

OBJECTIVE

This study sought to primarily describe the extent of Active Duty Soldiers' over-fatness when attending the initial ABCP nutrition class at an Army Nutrition clinic in Washington State; and secondarily to describe the proportion of these Soldiers meeting metabolic syndrome (MS) criteria.

METHODS

Soldiers (189) in this cross-sectional study completed the following: a questionnaire developed for this study, anthropometric measurements, body fat assessment via AR 600-9 standards, and a laboratory blood draw for fasting glucose and lipid panel.

RESULTS

Soldiers were predominantly male (76%), obese (BMI 32 kg/m2 for males and 30 kg/m2 for females), exceeded body fat standards by 3.8% for males and 7.3% for females, and 16% had three or more risk factors meeting MS diagnostic criteria. Waist circumference was the predominant MS risk factor for males and females.

CONCLUSION

Soldiers in this study had higher body fat percentages than expected with a majority of Soldiers classified as obese. Achieving and maintaining ABCP standards may be more challenging for obese Soldiers. To maintain Soldier readiness, commanders should consider intervening earlier when signs of weight gain are observed.

Trajectories of body mass index among active-duty U.S. Army soldiers, 2011-2014

Establishing the shape and determinants of trajectories of body mass index (BMI) among Soldiers is critical given the importance of weight management to military service requirements. To establish the shape and determinants of BMI trajectories among Soldiers, we aimed to (1) model the overall BMI trajectory of Soldiers, (2) find the most common trajectory groups among Soldiers, (3) investigate the relationship between BMI trajectories and sociodemographic and military-specific characteristics, and (4) determine if there were Soldiers with large fluctuations in BMI. The study population included all US Army Soldiers on active-duty between 2011 and 2014 who were age 17–62 (n = 827,126). With longitudinal data from the Stanford Military Data Repository, we used group-based trajectory modeling to identify the BMI trajectories of Soldiers and multinomial logistic regression to estimate associations between Soldier characteristics and trajectory membership. Four distinct BMI trajectory groups were found: increasing, decreasing, constant, and inconstant. The constant, increasing, and decreasing trajectories were similar in shape and percentage between men and women. The constant trajectory had the fewest Soldiers who exceeded weight standards or had duty limitations. The increasing trajectory was associated with marriage and fewer service years. The decreasing trajectory was associated with more service years and higher educational attainment. The inconstant trajectory differed in shape between men and women. Over 6% of men and 12% of women had fluctuations in BMI indicative of weight cycling. Understanding the characteristics associated with BMI trends may assist the Army in targeting resources aimed to improve Soldier health and combat readiness.

•

Four BMI trajectory groups were found: increasing, decreasing, constant, inconstant.

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The constant trajectory had the fewest Soldiers who exceeded weight standards.

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The increasing trajectory was associated with marriage and fewer service years.

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The decreasing trajectory was associated with more service years and education.

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6% of men and 12% of women had fluctuations in BMI indicative of weight cycling.

Revisiting the United States Army body composition standards: a receiver operating characteristic analysis

BACKGROUND

The objective for percent body fat standards in the United States Army Body Composition Program (ABCP) is to ensure soldiers maintain optimal well-being and performance under all conditions. However, conducting large-scale experiments within the United States Army to evaluate the efficacy of the thresholds is challenging.

METHODS

A receiver operating characteristic (ROC) analysis with corresponding area under the curve (AUC) was performed on body mass index (BMI) and waist circumference to determine optimal gender-specific age cohort thresholds that meet ABCP percent body fat standards in the National Health and Nutrition Examination Survey (NHANES) III. A second dataset consisting of a cohort of basic training recruits (N = 20,896 soldiers, 28% female) with BMI and waist circumference measured using a 3D body image scanner was applied to calculate what percent of basic training recruits meet the ABCP percent body fat standards. Regression models to determine the contribution of different circumference sites to the predictions of percent body fat were developed using a database compiled at the New York Obesity Research Center (N = 500).

RESULTS

Optimal BMI thresholds ranged from 23.65 kg/m² (17-21-year-old cohort) to 26.55 kg/m² (40 and over age cohort) for males and 21.75 to 24.85 kg/m² for females. The AUC values were between 0.86 and 0.92. The waist circumference thresholds ranged 81.35 to 97.55 cm for males and 77.05 to 89.35 cm for females with AUC values between 0.90 and 0.91. These BMI thresholds were exceeded by 65% of male and 74% of female basic training recruits and waist circumference thresholds were exceeded by 73% of male and 85% of female recruits. The single circumference that contributed most to prediction of body fat was waist circumference in males and mid-thigh circumference in females.

CONCLUSIONS

The ABCP percent body fat thresholds yield BMI thresholds that are below the United States Army BMI standards, especially in females which suggests the ABCP percent body fat standards may be too restrictive. The United States Army percent body fat standards could instead be matched to existing national health guidelines.

The association between obesity related health risk and fitness test results in the British Army personnel

OBJECTIVE

In the British Army, fitness is assessed by a load carriage test (Annual Fitness Test, AFT) and by a three event Personal Fitness Assessment (PFA). Body composition based on body mass index (BMI) and abdominal circumference (AC) is also part of a mandatory annual assessment. This study examined the influence of BMI and AC on fitness test results within a comprehensive sample of British Army personnel.

DESIGN

Secondary analyse were carried out on data obtained from the 2011 Defence Analytical Services and Advice (DASA) database for 50,635 soldiers (47,173 men and 3,462 women).

METHODS

Comparisons using loglinear analysis were made between groups of individuals classified by body mass index as obese (≥30kg/m2) and not obese (<30kg/m2), and further classified using combined BMI and AC for obesity-related health risks to compare "no risk" with "increased risk."

RESULTS

Not obese or "no risk" soldiers had a significant relationship with success in the AFT (p<0.01) and PFA (p<0.01). Of those soldiers who attempted the AFT, 99% of men and 92% of women passed; for the PFA, 92% of men and 91% of women passed. Obese or "at risk" soldiers were more likely to fail and far less likely to take both tests (p<0.05). Compared to older obese soldiers, young obese soldiers were more likely to attempt the tests.

CONCLUSIONS

We conclude that BMI and AC are useful indicators of fitness test outcome in the British Army.