Longitudinal changes in adverse effects reporting in multiple dietary supplement classifications: The US military dietary supplement use study.

Over 70% of United States military service members (SMs) regularly use dietary supplements (DSs) and about 18% have reported adverse effects (AEs) associated with use. This investigation examined longitudinal changes in AEs reporting among DS users. On two separate occasions 1.3 ± 0.2 years apart (mean ± standard deviation), 5778 SMs completed identical questionnaires on DS use and associated AEs. Among SMs reporting DS use ≥1 time/week, ≥1 AE was reported by 19% and 15% in the baseline and follow-up phases, respectively. The risk of reporting DS use at follow-up was similar among those reporting and not reporting AEs at baseline for most DS categories including prohormones, proteins/amino acids, individual vitamins and minerals, multivitamin/multiminerals, herbals, fish oils, joint health products, and other DSs. An exception was combination products where those reporting AEs at baseline had an increased risk of use at follow-up (risk ratio = 1.13, 95% confidence interval = 1.06-1.09). Those reporting AEs at baseline and continuing DS use in the follow-up were more likely to report AEs at follow-up compared to those not reporting baseline AEs. In conclusion, AEs reported at baseline did not deter many participants from using DSs in the follow-up period, and many SMs reporting AEs at baseline continued reporting them at follow-up.

Prevalence and adverse effects of sport-related nutritional supplements (sport drinks, bars, and gels) in the military before and during the COVID-19 pandemic: the US Military Dietary Supplement Use Study.

BACKGROUND: Sport-related nutritional supplements (SRNS) include sport drinks, sport bars, and sport gels. This investigation examined temporal patterns in SRNS use and adverse effects (AEs) reported by a single cohort of United States active-duty service members (SMs) surveyed before and during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: A stratified random sample (n = 22,858) of SMs (Air Force, Army, Navy, and Marine Corps) who completed a questionnaire on their SRNS use and AE experiences and were still on active duty were asked to complete the identical questionnaire on a second occasion. Twenty-five percent of successfully contacted SMs completed both questionnaires (n = 5,778) and were included in this investigation. The average ± standard deviation time between questionnaires was 1.3 ± 0.2 years. RESULTS: Prevalence of reported SRNS use ≥1 time/week in the baseline (BL) and follow-up (FU) phases were as follows: any SRNS: BL = 46%, FU = 41%; sport drinks: BL = 31%, FU = 28%; sport bars: BL = 30%, FU = 24%; sport gels: BL = 4%, FU = 4%. Reported weekly aerobic and resistance training durations were reduced in the FU period (8% and 26%, respectively). The proportion of SMs reporting SRNS use in both study phases was as follows: any SRNS = 62%, sport drinks = 54%, sport bars = 50%, sport gels = 35%. Prevalence of reported AEs in the BL and FU phases were as follows: any SRNS: BL = 1.9%, FU = 1.9%; sport drinks: BL = 1.0%, FU = 1.3%; sport bars: BL = 1.7%, FU = 1.4%; sport gels: BL = 3.3%, FU = 2.5%. The proportion of SMs reporting AEs in both phases was as follows: any SRNS = 14%, sport drinks = 11%, sport bars = 17%, sport gels = 0%. CONCLUSIONS: Overall SRNS use prevalence decreased slightly in the FU period, possibly because of reduced physical training related to military restrictions imposed during the emergence of COVID-19 between surveys. A large proportion of SMs reported changing their use patterns in the FU with some discontinuing use and others initiating use. The AE incidence was similarly low in the BL and FU phases, and few SMs reported AEs in both phases suggesting AEs were transitory. AE reporting for SRNSs was much lower than previously found for dietary supplements, possibly because of greater government regulatory control over SRNSs.

The Medical Burden of Obesity and Overweight in the US Military: Association of BMI with Clinically Diagnosed Medical Conditions in United States Military Service Members.

BACKGROUND: A high BMI is associated with various medical conditions, notably type 2 diabetes, cardiovascular disease, and mental health disorders. In the US military, BMI increased linearly between 1975 and 2015. OBJECTIVE: This cross-sectional study investigated the associations between BMI and a comprehensive range of clinically diagnosed medical conditions (CDMCs) in US military service members (SMs). METHODS: A stratified random sample of SMs (n=26,177) completed an online questionnaire reporting their height, weight, and demographic/lifestyle characteristics. Medical conditions for 6 mo before questionnaire completion were obtained from a comprehensive military electronic medical surveillance system and grouped into 39 CDMCs covering both broad (largely systemic) and specific medical conditions. BMI was calculated as weight/height2 (kg/m2). The prevalence of CDMCs was compared among normal weight (<25.0 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30 kg/m2) SMs. RESULTS: After multivariable adjustment for demographic/lifestyle characteristics, higher BMI was associated with higher odds of a diagnosed medical condition in 30 of 39 CDMCs, with all 30 displaying dose-response relationships. The 5 major CDMCs with the largest odds ratios comparing obese to normal weight were endocrine/nutritional/metabolic diseases (OR=2.67, 95%CI=2.24-3.15), nervous system diseases (odds ratio [OR]=2.59, 95%CI=2.32-2.90), circulatory system diseases (OR=2.56, 95%CI=2.15-3.06), musculoskeletal system diseases (OR=1.92, 95%CI=1.76-2.09), and mental/behavioral disorders (OR=1.69, 95%CI=1.51-1.90). Compared with normal weight SMs, overweight or obese SMs had a higher number of CDMCs (1.8±1.9 vs. 2.0±2.0 and 2.5±2.3, mean ± standard deviation, respectively, P<0.01). CONCLUSIONS: In a young, physically active population, higher BMI was associated with a host of medical conditions, even after adjustment for demographic/lifestyle characteristics. The US Department of Defense should improve nutrition education and modify other factors that contribute to overweight and obesity. This study demonstrates that the medical burden of obesity is substantial in overweight and obese SMs.

Biomarkers of oxidative stress, diet and exercise distinguish soldiers selected and non-selected for special forces training.

INTRODUCTION: The metabolomic profiles of Soldiers entering the U.S. Special Forces Assessment and Selection course (SFAS) have not been evaluated. OBJECTIVES: To compare pre-SFAS blood metabolomes of Soldiers selected during SFAS versus those not selected, and explore the relationships between the metabolome, physical performance, and diet quality. METHODS: Fasted blood samples and food frequency questionnaires were collected from 761 Soldiers prior to entering SFAS to assess metabolomic profiles and diet quality, respectively. Physical performance was assessed throughout SFAS. RESULTS: Between-group differences (False Discovery Rate < 0.05) in 108 metabolites were detected. Selected candidates had higher levels of compounds within xenobiotic, pentose phosphate, and corticosteroid metabolic pathways, while non-selected candidates had higher levels of compounds potentially indicative of oxidative stress (i.e., sphingomyelins, acylcarnitines, glutathione, amino acids). Multiple compounds higher in non-selected versus selected candidates included: 1-carboxyethylphenylalanine; 4-hydroxy-nonenal-glutathione; α-hydroxyisocaproate; hexanoylcarnitine; sphingomyelin and were associated with lower diet quality and worse physical performance.  CONCLUSION: Candidates selected during SFAS had higher pre-SFAS levels of circulating metabolites that were associated with resistance to oxidative stress, higher physical performance and higher diet quality. In contrast, non-selected candidates had higher levels of metabolites potentially indicating elevated oxidative stress. These findings indicate that Soldiers who were selected for continued Special Forces training enter the SFAS course with metabolites associated with healthier diets and better physical performance. Additionally, the non-selected candidates had higher levels of metabolites that may indicate elevated oxidative stress, which could result from poor nutrition, non-functional overreaching/overtraining, or incomplete recovery from previous physical activity.

Associations between clinically diagnosed medical conditions and dietary supplement use: the US military dietary supplement use study.

OBJECTIVE: This study examined associations between multiple dietary supplement (DS) categories and medical conditions diagnosed by health professionals. DESIGN: Cross-sectional. SETTING: Volunteers completed an online questionnaire on DS use and demographic/lifestyle factors. Medical diagnoses were obtained from a comprehensive military electronic medical surveillance system and grouped into twenty-four clinically diagnosed medical conditions (CDMC). PARTICIPANTS: A stratified random sample of US service members (SM) from all military services (n 26 680). RESULTS: After adjustment for demographic/lifestyle factors (logistic regression), higher risk was found for 92 % (22/24) of CDMC among individual vitamins/minerals users, 58 % (14/24) of CDMC among herbal users, 50 % (12/24) of CDMC among any DS users and 46 % (11/24) of CDMC among multivitamins/multiminerals (MVM) users. Among protein/amino acid (AA) users, risk was lower in 25 % (6/24) of CDMC. For combination products, risk was higher in 13 % (3/24) of CDMC and lower in 8 % (2/24). The greater the number of CDMC, the higher the prevalence of DS use in most DS categories except proteins/AA where prevalence decreased. CONCLUSIONS: Users in many DS categories had a greater number of CDMC, but protein/AA users had fewer CDMC; results for combination products were mixed. These data indicate those with certain CDMC were also users in some DS categories, especially individual vitamins/minerals, herbals and MVM. Data are consistent with the perception that use of DS enhances health, especially in those with CDMC. Protein/AA and combination product users were more likely to be younger, more physically active men, factors that likely reduced CDMC.

Association of Body Mass Index with Injuries: A Systematic Review and Meta-Analyses Comparing Healthy Weight Military Service Members with Underweight, Overweight, and Obese.

Obesity is a worldwide health problem that has reached pandemic proportions. In the military, obesity and overweight are associated with health problems, attrition from military service, and reduced job performance. National and international organizations suggest body mass index (BMI) as a population screening tool to define overweight and obesity. BMI is calculated as weight/height2 (kg/m2). Four categories of adult BMI are underweight (<18.5 kg/m2), healthy weight (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (=30.0 kg/m2). This article reports on a systematic review and meta-analysis examining the association between BMI and injury risk among military service members (SMs). Studies were selected for review if they involved military personnel, were prospective or retrospective observational studies, and contained original quantitative data on injury risk at all four BMI levels. Nine studies met the review criteria. Pooled data from these investigations indicated that underweight, overweight, and obese individuals were at 1.17 (95% confidence interval [95%CI]=1.07-1.28), 1.03 (95%CI=1.01-1.06), and 1.15 (95%CI=1.11-1.20) times higher risk of injury than healthy weight individuals, respectively. Compared with healthy weight SMs, military personnel with both low and high BMI are at higher injury risk.

The Presence of Hip Joint Effusion on MRI Is Predictive of a Grade 4 Femoral Neck Stress Injury.

INTRODUCTION: One of the most debilitating types of bone stress injuries is those occurring at the femoral neck. This problem occurs in the military population with much higher incidence than in the normal population and is of great concern to military medical providers. Early detection and accurate diagnosis are key in protecting soldiers and recruits from sustaining a potentially career-ending fracture. In a case study, a 16-year-old elite male distance runner presented with hip pain. MRI found hip joint effusion but was unremarkable for marrow edema and a low-signal fracture line. The initial diagnosis was acute arthritis; however, a follow-up radiograph 1 month later, after the patient had been refraining from running, confirmed a significant non-displaced compression-side Grade 4 femoral neck stress injury (FNSI). In light of the case study and our similar clinical experience, we tested the hypothesis that an MRI study positive for an FNSI, combined with the evidence of a hip joint effusion, is indicative of a Grade 4 FNSI, even without visualization of a low-signal intensity fracture line on T1 or short tau inversion recovery images. MATERIALS AND METHODS: Recruits in Army Basic Combat Training were included in the investigation if 1) diagnosed with a unilateral FNSI, 2) had an initial positive MRI for an FNSI, 3) had a positive bone scan for uptake in the femoral neck area (to validate the diagnosis), 4) had no other hip/pelvis injuries, and 5) had a follow-up MRI within 60 days. Hip joint effusion was defined as 1) ≥2-mm measurable difference in the thickness of fluid along the length of the involved femoral neck when compared to the contralateral uninvolved femoral neck on the initial MRI; 2) visibly assessed as a prominent collection of fluid distending the posterior hip joint capsule on the initial MRI coronal short tau inversion recovery sequence (called the "flash sign"). RESULTS: A total of 162 recruits met the study inclusion criteria. For the detection of a Grade 4 FNSI on the first MRI, the sensitivity, specificity, and positive predictive value of the measured joint effusion criteria were 0.52, 0.94, and 0.89, respectively. or the non-measured flash sign, these values were 0.70, 0.83, and 0.80, respectively. CONCLUSIONS: Both the measured hip joint effusion criteria and the non-measured flash sign were predictive of a Grade 4 FNSI and may be useful in clinical evaluation.

Short sleep duration is associated with a wide variety of medical conditions among United States military service members.

OBJECTIVES: This cross-sectional study investigated self-reported sleep duration and its association with a comprehensive range of clinically-diagnosed medical condition categories (CDMCs), as well as the relationship between short sleep duration (≤6 h) and demographic/lifestyle factors, among United States military service members (SMs). METHODS: A stratified random sample of SMs (n = 20,819) completed an online questionnaire on usual daily hours of sleep and demographic/lifestyle characteristics. CDMCs for a six-month period prior to questionnaire completion were obtained from a comprehensive military electronic medical surveillance system and grouped into 33 CDMCs covering both broad and specific medical conditions. Prevalence of CDMCs was compared among three sleep duration categories (≤4, 5-6 and ≥7 h). RESULTS: SMs reported a mean ± standard deviation of 6.3 ± 1.4 h of sleep per day. After adjustment for demographic/lifestyle characteristics, shorter sleep duration was associated with higher odds of a medical condition in 25 of 33 CDMCs, with most (n = 20) demonstrating a dose-response relationship. The five CDMCs with the largest differences between ≤4 vs ≥ 7 h sleep were: diseases of the nervous system (odds ratio [OR] = 2.9, 95% confidence interval [95%CI] = 2.4-3.4), mental/behavioral diseases (OR = 2.7, 95%CI = 2.3-3.2), diseases of the musculoskeletal system (OR = 1.9, 95%CI = 1.6-2.1), diseases of the circulatory system (OR = 1.7, 95%CI = 1.3-2.2), and diseases of the digestive system (OR = 1.6, 95%CI = 1.2-2.0). Six hours of sleep or less was independently associated with older age, less formal education, race, Hispanic ethnicity, higher body mass index, smoking, and military service branch. CONCLUSIONS: In this young, physically active population, reporting shorter sleep duration was associated with a higher risk of multiple CDMCs.

Sleep and Injuries in Military Personnel With Suggestions for Improving Sleep and Mitigating Effects of Sleep Loss.

Sleep professionals suggest adults should sleep at least seven hours per night and define good sleep quality as 1) sleep onset =15 minutes, 2) one or fewer awakenings per night, 3) awake after sleep onset =20 minutes, and 4) sleep efficiency (ratio of sleep time to time in bed) =85%. This paper focuses on associations between injuries and sleep quality/duration among military personnel and strategies to optimize sleep and mitigate effects of sleep loss. Investigations among military personnel generally used convenience samples who self-reported their injury and sleep quality/quantity. Despite these limitations, data suggest that lower sleep quality or duration is associated with higher risk of musculoskeletal injury (MSI). Possible mechanisms whereby poor sleep quality/duration may influence MSI include hormonal changes increasing muscle catabolism, increases in inflammatory processes affecting post-exercise muscle damage, and effects on new bone formation. Sleep can be optimized by a slightly cool sleeping environment, bedding that maintains a stable thermal microclimate around the body, not using media devices near bedtime or in the sleeping environment, minimizing noise, and having regular bed and awaking times. Sleep loss mitigation strategies include napping (<30 to 90 minutes), sleep banking (extended time in bed), and judicious use of caffeine or modafinil.

Prescription medication use of United States military service members by therapeutic classification.

Background: This cross-sectional study investigated the prevalence of, and factors associated with, filled prescription medications (FPMs) among United States (US) service members (SMs). Methods: A stratified random sample of active duty SMs from the Air Force, Army, Marine Corps, and Navy was obtained from military workforce records. Participants (n = 26,680) completed a questionnaire on demographics, physical characteristics, and lifestyle factors and approved access to their FPM for the previous 6 months. FPMs were obtained from the military Pharmacy Data Transaction Service that included all prescription medications dispensed at military medical treatment facilities, abroad, at retail pharmacies in the US, and/or through mail-order programs. Results: About two-thirds (65%) of SMs had ≥1 FPM in the 6 months surveillance period. Central nervous system (CNS) agents had the highest prevalence (41%), followed by anti-infective agents (20%), eye/ear/nose/throat preparations (20%), gastrointestinal drugs (18%), autonomic drugs (17%), skin and mucous membrane agents (13%), antihistamine drugs (12%), respiratory tract agents (12%) and cardiovascular drugs (9%). Among CNS agents, overall prevalence of dispensed non-steroidal anti-inflammatory drug (NSAIDs) was 30%. The odds of any FPM was independently associated with female gender, older age, higher body mass index, former tobacco use (smoking and smokeless tobacco), lower alcohol consumption, and was highest among Army, lowest among Marine Corps personnel. Conclusion: In this sample of SMs, dispensing of prescription medication was high, especially NSAIDs, but dispensing of cardiovascular drugs was much lower compared to the general US population, likely because of the younger age and higher level of physical activity of SMs.

Obstacle Course Events: Hazards and Prevention Measures.

This article reviews hazards associated with obstacle course events (OCEs) like the Spartan Race and Tough Mudder, which are becoming increasingly popular, and provides strategies to mitigate these hazards. In seven studies, the overall weighted incidence of participants seeking medical care during OCEs was only 1.4% with ~6% of these requiring higher level medical care at a hospital. Nonetheless, 27% of participants self-reported =1 extremity injury. Common OCE medical problems included sprains/strains and dermatological injuries (abrasions/laceration/blisters); the ankle and knee were common injury locations. There are reports microorganism infections during OCEs, associated with ingestion of contaminated water and mud. On military obstacle courses, ~5% were injured, but this activity has the highest injury rate (injuries/hour of training) of all major testing or training activities. Ankle sprain risk can be reduced with proprioceptive training and prophylactic ankle bracing. Knee injury risk can be reduced with exercise-based programs that incorporate various components of proprioceptive training, plyometrics, resistance exercises, stretching, and shuttle/bounding running. Reducing abrasions and lacerations involve wearing low friction clothing, gloves, and prophylactic covering of skin areas prone to abrasions/lacerations with specific protective materials. Reducing blister likelihood involves use of antiperspirants without emollients, specialized sock systems, and covering areas prone to blisters with paper tape. Reducing infections from microorganism can be accomplished by protective covering open wounds, rinsing off mud post-race, and avoiding ingestion of food and drink contaminated with mud. These chiefly evidence-based injury and illness prevention measures should minimize the risks associated with OCEs.

Dietary Supplement and Prescription Medication Use Among US Military Service Members With Clinically Diagnosed Medical Conditions: The US Military Dietary Supplement Use Study.

BACKGROUND: Use of prescription medications (PMs) with dietary supplements (DSs) can be hazardous because of potential adverse interactions, but patterns of dual use in military service members (SMs) has not been examined. OBJECTIVE: Investigate dual use of filled PMs (FPMs) and DSs, factors associated with dual use, and dual use among SMs with clinically diagnosed medical conditions (CDMCs). DESIGN: Cross-sectional. Data on FPMs and CDMCs were obtained from medical surveillance records. Between December 2018 and August 2019, participants completed a questionnaire on DS use in the previous 6 months. PARTICIPANTS: A stratified random sample of 26,880 SMs from all military services. MAIN OUTCOME MEASURES: Prevalence of dual use of FPMs with DSs within a 6-month period, demographic/lifestyle factors associated with dual use, and prevalence of dual use among SMs with CDMCs. STATISTICAL ANALYSIS: Prevalences were calculated as percents, χ2 statistics examined differences across various strata of demographic and lifestyle characteristics, and univariable and multivariable logistic regression determined the odds of using FPMs with DSs for various CDMCs. RESULTS: About one-half (49%) of SMs had dual use of FPMs with DSs in the 6-month period. Dual use was higher among women; increased with older age, more formal education, higher body mass index, and more physical activity; was highest among American Indian SMs and lowest among Asian SMs; was higher among former tobacco users; and was highest among Army personnel and lowest among Marine Corps personnel. The overall prevalence of dual use in the 6-month period was higher among those with a CDMC than those without (62% vs 19%), and this relationship was maintained for 20 International Classification of Diseases, Revision 10, code groupings covering virtually all CDMCs. CONCLUSION: This is the first study to document a high prevalence of dual FPMs and DSs in SMs, especially among those with CDMCs.

Prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among active duty United States military personnel.

BACKGROUND: Although representative data on caffeine intake in Americans are available, these data do not include US service members (SMs). The few previous investigations in military personnel largely involve convenience samples. This cross-sectional study examined prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among United States active duty military service members (SMs). METHODS: A stratified random sample of SMs were asked to complete an on-line questionnaire on their personal characteristics and consumption of caffeinated products (exclusive of dietary supplements). Eighteen percent (n = 26,680) of successfully contacted SMs (n = 146,365) completed the questionnaire. RESULTS: Overall, 87% reported consuming caffeinated products ≥1 time/week. Mean ± standard error per-capita consumption (all participants) was 218 ± 2 and 167 ± 3 mg/day for men and women, respectively. Caffeine consumers ingested 243 ± 2 mg/day (251 ± 2 mg/day men, 195 ± 3 mg/day women). On a body-weight basis, men and women consumed respectively similar caffeine amounts (2.93 vs 2.85 mg/day/kg; p = 0.12). Among individual caffeinated products, coffee had the highest use (68%), followed by sodas (42%), teas (29%), energy drinks (29%) and gums/candy/medications (4%). In multivariable logistic regression, characteristics independently associated with caffeine use (≥1 time/week) included female gender, older age, white race/ethnicity, higher body mass index, tobacco use or former use, greater alcohol intake, and higher enlisted or officer rank. CONCLUSION: Compared to National Health and Nutrition Examination Survey data, daily caffeine consumption (mg/day) by SMs was higher, perhaps reflecting higher mental and physical occupational demands on SMs.

Injuries During High-Intensity Functional Training: Systematic Review and Meta-Analysis.

High-intensity functional training (HIFT) involves high-volume and high-intensity physical activities with short rest periods between movements and use of multiple joint exercises. This article reports the results of a systematic review and meta- analysis of studies involving injuries during HIFT. Individual studies were selected for review if they involved individuals =18 years of age and provided quantitative data on injury prevalence and/or injury rates during HIFT. Twenty-eight studies involving 11,089 participants met the inclusion criteria. There was considerable variability in individual studies with injury prevalences ranging from 12% to 74% and injury rates from 0.04 to 18.90 injuries/1000 h of training. Meta-analyses indicated that the overall injury prevalence was 36% (95% confidence interval [95% CI] = 32-41%) and overall injury rate 4.3 injuries/1000 h (95% CI = 3.35-5.23). Injury rates among the five available prospective cohort studies was considerably higher, 9.9 injuries/1000 h (95% CI = 3.3-16.4). The most commonly injured anatomical locations (with % of total injuries) were the shoulder (26%), back/spine (26%), knee (14%), wrist/hands/fingers (12%), arm/elbow (10%), and ankle/foot (6%). Given the higher injury rates among prospective studies that likely more effectively tracked injuries over time, more prospectively designed studies are required before the injury rate during HIFT can be appropriately quantified.

Adverse Effects Associated with Multiple Categories of Dietary Supplements: The Military Dietary Supplement Use Study.

BACKGROUND: About 50% of Americans and 70% of US military service members (SMs) regularly use dietary supplements (DSs) and some are associated with adverse effects (AEs). SMs are more likely to use unsafe DSs than civilians. OBJECTIVE: The aim of this investigation was to examine the prevalence of, and factors associated with, AEs. DESIGN: Cross-sectional. PARTICIPANTS: A stratified random sample of 200,000 US SMs from the Air Force, Army, Marine Corps, and Navy were obtained from military workforce records. Eighteen percent (n = 26,681) of successfully contacted SMs (n = 146,365) volunteered to participate between December 2018 and August 2019. Participants completed a detailed online questionnaire on demographic characteristics, lifestyle factors, and AEs associated with DS use. MAIN OUTCOME MEASURE: Prevalence of, and factors associated with, AEs among DS users. STATISTICAL ANALYSIS: Prevalence of AEs was calculated by DS categories. Linear trends, χ2 statistics, and multivariable logistic regression examined associations between AEs and demographic characteristics, lifestyle factors, and number DSs consumed. RESULTS: Proportion of DS users (≥ 1 time /week) reporting ≥1 AE was 18% overall, 20% for combination products (ie, weight loss, muscle building, and before/after workout supplements), 8% for purported prohormones, 6% for protein/amino acid products, 6% for multivitamin/multiminerals, 6% for individual vitamins/minerals, 4% for herbal products, and 2% for joint health products. Combination products are very popular in military personnel with nearly half of SMs regularly taking them. In multivariable analysis, reporting AEs were independently associated with female gender, younger age, higher body mass index, smoking, higher alcohol intake, service in the Army, Navy, or Marine Corps (compared with Air Force), and consumption of a greater number of DSs. CONCLUSIONS: A large proportion of SMs report experiencing AEs, especially users of combination products and purported prohormone supplements. This study presents contemporary data collected from a very large at-risk population on potentially hazardous categories of DSs.

Adverse effects associated with use of specific dietary supplements: The US Military Dietary Supplement Use Study.

Dietary supplements (DSs) are used by 50% of Americans and 70% of United States military service members (SMs); some have adverse effects (AEs). This cross-sectional investigation examined AEs associated with specific DSs. A stratified random sample of SMs from the Air Force, Army, Marine Corps, and Navy was obtained. Volunteers completed a questionnaire reporting AEs for 96 generic and 62 specific DSs. The highest prevalence (≥1 AE) in specific DS categories was 35% prohormones, 33% weight loss supplements, 26% pre/post workout supplements, 14% herbal products, 12% multivitamin/multiminerals, 11% protein/amino acids, 9% muscle building supplements, 7% other DSs, 6% joint health products, and 5% individual vitamins/minerals. Specific DSs of concern (with proportion reporting AEs) included: Libido Max® (35%), Hydroxycut Hardcore® (33%), OxyElite® (33%), Roxylean® (31%), Growth Factor 9® (30%), Super HD® (29%), Hydroxycut Advanced® (29%), Lipo 6® (28%), The Ripper® (27%), Test Booster® (27%), Xenadrine Xtreme Thermogenic® (27%), C4 Extreme® (26%), and C4 Original® (25%). Products marketed for weight loss, use before/after workout, and prohormones had the highest AE prevalence. DSs can contain substances with independent/additive AEs and/or interact with other ingredients or prescribed medications. Methods described here could provide a continuous surveillance system detecting dangerous DSs entering the market.

Anthropometrics and Body Composition Predict Physical Performance and Selection to Attend Special Forces Training in United States Army Soldiers.

INTRODUCTION: Anthropometrics and body composition characteristics differentiate many types of athletes and are related to performance on fitness tests and tasks in military personnel. Soldiers competing to enter elite units must demonstrate physical fitness and operational competence across multiple events. Therefore, this study determined whether anthropometrics and body composition predicted physical performance and selection for special forces training among soldiers attending the rigorous Special Forces Assessment and Selection (SFAS) course. MATERIALS AND METHODS: Soldiers attending the SFAS course between May 2015 and March 2017 were enrolled in a longitudinal, observational study. Anthropometrics (height, body mass, and body mass index [BMI]; n = 795) and body composition measured by dual-energy X-ray absorptiometry (percentage body fat, fat mass, lean mass, bone mineral content [BMC], and bone mineral density [BMD]; n = 117) were assessed before the course start. Associations with physical performance were determined with correlation coefficients. Associations with selection were determined with analyses of variance and t-tests; effect sizes were calculated as Cohen's d. The U.S. Army Research Institute of Environmental Medicine Institutional Review Board (IRB) initially approved this study, and the U.S. Army Medical Research and Development Command IRB approved the continuing review. RESULTS: Lower percentage body fat and fat mass predicted better performance on all assessments: Army Physical Fitness Test (APFT), pull-ups, SFAS run, loaded road march, obstacle course, and land navigation (P ≤ .05). Higher lean mass predicted better performance on the loaded road march (P ≤ .05). Lower body mass and BMI predicted better performance on APFT, pull-ups, run, and obstacle course; higher body mass and BMI predicted better performance on the loaded road march (P ≤ .05). Shorter stature predicted better performance on push-ups (APFT) and pull-ups; taller stature predicted better performance on SFAS run and loaded road march (P ≤ .05). On average, the selected soldiers were taller (179.0 ± 6.6 vs. 176.7 ± 6.7 cm), had higher body mass (85.8 ± 8.8 vs. 82.1 ± 9.6 kg), BMI (26.8 ± 2.2 vs. 26.3 ± 2.6 kg/m2), lean mass (67.2 ± 7.3 vs. 61.9 ± 7.6 kg), BMC (3.47 ± 0.40 vs. 3.29 ± 0.56 kg), and BMD (1.34 ± 0.10 vs. 1.28 ± 0.10 g/cm2), and lower percentage body fat (17.3 ± 3.4 vs. 20.1 ± 4.5%) and fat mass (14.2 ± 3.7 vs. 15.8 ± 4.4 kg) (P ≤ .05). Effect sizes were largest for lean mass (Cohen's d = 0.71) and percentage body fat (d = 0.70), followed by BMD (d = 0.60), body mass (d = 0.40), fat mass (d = 0.39), BMC (d = 0.37), height (d = 0.35), and BMI (d = 0.21). Body mass adjustment attenuated associations between height and selection. CONCLUSIONS: Anthropometrics and body composition are predictors of physical performance and SFAS success. Since these measures are modifiable (excluding height), they may be the focus of intervention studies aiming to improve performance in arduous military training courses, sports that require competition in multiple events, and occupations that have varied physical demands, such as firefighting, law enforcement, and construction.

Accuracy of Metabolic Cost Predictive Equations During Military Load Carriage.

ABSTRACT: Vine, CA, Coakley, SL, Blacker, SD, Doherty, J, Hale, B, Walker, EF, Rue, CA, Lee, BJ, Flood, TR, Knapik, JJ, Jackson, S, Greeves, JP, and Myers, SD. Accuracy of metabolic cost predictive equations during military load carriage. J Strength Cond Res 36(5): 1297-1303, 2022-To quantify the accuracy of 5 equations to predict the metabolic cost of load carriage under ecologically valid military speed and load combinations. Thirty-nine male serving infantry soldiers completed thirteen 20-minute bouts of overground load carriage comprising 2 speeds (2.5 and 4.8 km·h-1) and 6 carried equipment load combinations (25, 30, 40, 50, 60, and 70 kg), with 22 also completing a bout at 5.5 km·h-1 carrying 40 kg. For each speed-load combination, the metabolic cost was measured using the Douglas bag technique and compared with the metabolic cost predicted from 5 equations; Givoni and Goldman, 1971 (GG), Pandolf et al. 1997 (PAN), Santee et al. 2001 (SAN), American College of Sports Medicine 2013 (ACSM), and the Minimum-Mechanics Model (MMM) by Ludlow and Weyand, 2017. Comparisons between measured and predicted metabolic cost were made using repeated-measures analysis of variance and limits of agreement. All predictive equations, except for PAN, underpredicted the metabolic cost for all speed-load combinations (p < 0.001). The PAN equation accurately predicted metabolic cost for 40 and 50 kg at 4.8 km·h-1 (p > 0.05), underpredicted metabolic cost for all 2.5 km·h-1 speed-load combinations as well as 25 and 30 kg at 4.8 km·h-1, and overpredicted metabolic cost for 60 and 70 kg at 4.8 km·h-1 (p < 0.001). Most equations (GG, SAN, ACSM, and MMM) underpredicted metabolic cost while one (PAN) accurately predicted at moderate loads and speeds, but overpredicted or underpredicted at other speed-load combinations. Our findings indicate that caution should be applied when using these predictive equations to model military load carriage tasks.

Injuries During High-Intensity Functional Training.

High-intensity functional training (HIFT) involves high-volume and high-intensity physical activities with short rest periods between movements and the use of multiple-joint exercises. This paper analyzes narrative and systematic reviews covering studies of injuries sustained during HIFT. Two narrative and six systematic reviews on injuries during HIFT were identified. Seven reviews concluded that the injury incidences or injury rates during HIFT were similar to those of comparable sports and exercise programs. The most often injured anatomic locations were shoulders, backs, and knees. The most comprehensive and recent review involved 21 retrospective and three prospective studies. In this review, mean ± standard deviation (SD) injury prevalence was 35% ± 15%, the injury rate was approximately 3 ± 5 injuries/1,000 hours of training, and the prevalence of injuries requiring surgery was 6% ± 5%. Most injuries were associated with weightlifting exercises, especially deadlifts, snatches, clean and jerks, and overhead presses. Other risk factors included participation time in HIFT, participation in competition, prior injuries, weekly training frequency, male sex, older age, and alternating training loads. Although most studies included in these reviews were of lower methodologic quality, current evidence suggests that injury rates in HIFT are similar to those of other exercise activities. More high-quality prospective studies are needed to fully evaluate HIFT safety.

Update on Minimalist Running Shoes.

This article provides updated information comparing minimalist running shoes (MRS) to conventional running shoes (CRS). Our previous review found that, compared with running in CRS, transitioning to MRS resulted in lower energy cost and less ground contact occurring at the forefoot, resulting in lower impact forces. There was some increased risk of injury with MRS, although data were conflicting. A more recent 26-week study involved 30 trained runners using CRS and 31 using MRS. The proportion of training time in the assigned shoes increased by 5% each week. After the first 6 weeks of transition (35% of training time in the assigned shoe), energy cost was lower and 5-km running time faster in MRS compared with CRS. No further improvement occurred from weeks 6 to 26. There were no significant differences in injury incidence in the two groups (CRS = 37%, MRS = 52%; p = .24). Running-related pain was higher in the MRS group in the knee, shin, calf, and ankle and increased at these locations as running mileage increased. Risk of injury in MRS increased as participant body weight increased. These more recent data suggest that MRS can improve performance, but most runners should limit running in MRS to 35% of training time and in situations where optimal performance is desired (e.g., races, fitness tests).