Introduction:The U.S. Army's Holistic Health and Fitness (H2F) System addresses soldier readiness. One of the five domains of the H2F System is physical readiness. With the goal of optimizing physical performance and preventing injury, U.S. Army brigades were provided with physical training equipment, training facilities, and sports medicine teams (SMTs). This investigation assessed the effects of SMTs on soldiers' physical performance. Methods:A survey collected demographics and physical training time over a 1-yr period. Army Combat Fitness Test (ACFT) data were acquired through a surveillance system. Initial and follow-up ACFT performances were available for 399 male soldiers. Soldiers were divided into two groups: those with SMTs (SMT group, n = 323) and those without SMTs (no SMT group, n = 76). Multivariable linear regression was used to determine ACFT event performance estimates. Results:The SMT group spent more time resistance training (57.8 +/- 58.4 vs 40.8 +/- 36.5 min & centerdot;wk-1, P < 0.01) and less time performing calisthenics (36.9 +/- 41.2 vs 53.2 +/- 51.5 min & centerdot;wk-1, P = 0.04) compared with the no SMT group. Regression models revealed improved performance for the SMT group compared with no SMT group for all ACFT events: Deadlift +17.8 (+/- 5.8) lb, standing power throw +0.31 (+/- 0.14) m, hand release push-ups +2.7 (+/- 1.2) repetitions, sprint-drag-carry -0.11 (+/- 0.03) min or 7 s faster, leg tuck +1.4 (+/- 0.47) repetitions, and 2-mile run -0.51 (+/- 0.18) min or 31 s faster (P <= 0.03). Conclusion:After training for approximately 1 yr, soldiers with SMTs showed greater physical performance improvements compared with soldiers without SMTs.

OBJECTIVES:The purpose of this investigation was to examine the relationship between nutritional intake of a cohort of United States (US) Army Reserve Component (RC) Soldiers and physical performance as measured by the Army Combat Fitness Test (ACFT), total injuries, and cumulative micro-traumatic "overuse" musculoskeletal injury (MSKI). DESIGN:Retrospective cohort study. METHODS:A voluntary survey was administered to 21 US Army RC units from July to December 2021. Surveys collected demographic information, nutritional intake, and injuries in the previous 12 months. Nutritional intake was assessed by frequency of fruit, vegetable, whole grain, dairy, and protein intake. ACFT data were obtained from a centralized database. Multivariable linear and logistic regression models were used to estimate associations between nutritional intake, physical performance, and injury outcomes. RESULTS:A total of 1322 Soldiers (82.8% male) completed the survey. Controlling for sex, age, body mass index (BMI), and cumulative MSKI prior to the ACFT, soldiers reporting greater vegetable, whole grain, dairy, and protein intake (2-3 and 4+ servings per day) had better performance on hand release push up, sprint-drag-carry, leg tuck, and 2-mile run events compared to those reporting rarely or never (p < .05). After adjustment for sex, age, and BMI, estimated associations between nutritional intake and self-reported injuries were not statistically significant (p > .05). CONCLUSION:In this investigation, greater vegetable, whole grain, dairy, and protein intake was associated with better performance on anerobic and aerobic ACFT events but not related to odds of injury. These findings underscore the importance of healthy nutritional intake for physical readiness within the Reserve Component.

ABSTRACT:Pearson, RC, Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Changes in physical training and injury incidence following the introduction of a new military fitness test. J Strength Cond Res 39(5): e684-e691, 2025-Physical training (PT) and injury incidence may be affected by the implementation of a new physical fitness test. Current investigation measured changes in PT and injury incidence following field testing of the Army Combat Fitness Test (ACFT). Sixty-one battalions were administered electronic surveys before and after ACFT field testing from October 2018 through June 2020. Surveys collected demographics, injury incidence, and PT within the previous 12 months. Army Combat Fitness Test records were obtained from the Digital Training Management System. Statistical significance was accepted at p ≤ 0.05. One thousand one hundred thirty-four soldiers completed both surveys. Male soldiers represented 77% (31.3 ± 8.6 years, 21.3 ± 4.3 kg·m -2 ) and female soldiers represented 23% (30.0 ± 7.8 years, 24.1 ± 3.1 kg·m -2 ) of respondents. Male soldiers reported lower unit calisthenics training, higher unit resistance training, and higher unit total exercise following field testing (minutes per week, p < 0.05). Male soldiers reported higher personal running, higher personal resistance training, lower personal obstacle course training, and lower personal total exercise after field testing (minutes per week, p < 0.05). Female soldiers reported lower unit running, higher unit resistance training, higher personal resistance training, lower personal obstacle course training, and lower personal total exercise after field testing (minutes per week, p < 0.05). After field testing, male soldiers reported a greater number of lower back injuries (+2.9%, p = 0.01) and a greater number of resistance training injuries (+1.7%, p < 0.01). Changes in specific training modalities may lead to changes in activities associated with injury. Proper technique, periodization, individualization, and recovery education are recommended to control injury incidence when a new PT program is implemented.

Study Objectives: Determine the incidence of obstructive sleep apnea (OSA) among United States Army soldiers from 2014 through 2019 and assess self-reported impacts of the disorder and one of its treatments-oral appliance therapy.Methods: Surveillance data were obtained from the Armed Forces Health Surveillance Division; remaining data were self-reported through an electronic survey.Results: There were 87 404 cases of OSA from 2014 through 2019; incidence rates ranged from 274.3 to 330.3 cases per 10 000 personyears (p-yrs).Male incidence rates (from 294.3 to 355.9/10 000 p-yrs) exceeded female incidence rates (from 155.2 to 189.2/10 000 pyrs).Soldiers ≥40 years old had the highest incidence rates (from 820.1 to 973.2/10 000 p-yrs).The survey was completed by 8740 soldiers.The majority reported positive airway pressure therapy as their current treatment method; 9% (n=795) reported treatment with an oral appliance.Comparing pretreatment to post-treatment, respondents treated with the oral appliance reported statistically significant improvements in sleep quality, duration, and various aspects of daily life.The predominance (76%) of those treated with anything other than the oral appliance reported they were not aware of the oral appliance as a treatment method.Conclusion: Results suggest soldiers are satisfied with the oral appliance; it has significantly improved their sleep quality, duration, and various aspects of daily life.Clinical Implications: Military dentists can support a streamlined process to diagnose and treat OSA.The required yearly dental exam provides an opportunity to screen soldiers for OSA and discuss the lesser-known treatment-oral appliance therapy.

Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Relative Strength and Physical Performance in U.S. Army Male and Female Soldiers. J Strength Cond Res 38(8): 1479–1485, 2024—In occupations with high physical demands, strength relative to bodymass is an important measure as it signifies an individual's ability to control and move their body mass through space. The purpose of this investigation was to examine physical characteristics, training, and performance based on different magnitudes of relative strength. Subjects were 1,806 male and 319 female US Army soldiers. Sex, age, height, body mass, and physical training data were obtained by an electronic survey. Physical performance was measured by the Army Combat Fitness Test (ACFT), which includes a three-repetition maximum deadlift, standing power throw, hand release push-up, sprint-drag-carry, leg tuck, and two-mile run. The relative body mass deadlifted was calculated and categorized into 4 groups for men and 3 groups for women. An analysis of variance and post hoc least significant difference test were used to evaluate the differences in relative strength and physical performance. Overall, 33% of men deadlifted ≥1.5 times their body mass, while 30% of women deadlifted ≥1.25 times their body mass. Men and women deadlifting the highest percentage of their body mass (≥1.5 times for men and ≥1.25 times for women) outperformed those with lower relative strength within their own sex in all 6 ACFT events. In 4 of the 6 ACFT events, women who deadlifted ≥1.25 times their body mass had similar performance compared with men deadlifting 1 to 1.24 times their body mass and outperformed men deadlifting <1 times their body mass. Greater strength relative to body mass was associated with higher physical performance.

OBJECTIVES:Only one-third of U.S. Army Soldiers meet the recommended sleep guideline of 7 or more hours per night. Soldiers meeting the recommended sleep guideline are more likely to perform better on cognitive and physical tasks. The purpose of this analysis was to compare the physical and behavioral characteristics of Soldiers who met and did not meet the sleep recommendation guideline and determine associations between physical and behavioral characteristics and the acquisition of recommended amounts of sleep per night. METHODS:A survey was administered to U.S. Army Soldiers. Adjusted odds ratios and corresponding 95% confidence intervals were calculated to determine associations between achieving the recommended number of hours of sleep per night and age, physical characteristics, health behaviors, physical training, and physical performance. RESULTS:A survey was completed by 4229 men and 969 women. Male Soldiers who met the recommended sleep requirement had lower estimated body fat [20.3 ± 4.2% vs. 21.1 ± 4.4%], were less likely to use tobacco [11.5% vs. 16.2%] and exercised more [259 ± 226 vs. 244 ± 224 min/wk] compared with those who did not obtain 7 hours of sleep per night. Female Soldiers who met the recommended sleep requirement had lower estimated body fat [31.4 ± 4% vs. 32.1 ± 4.6%] and exercised more [258 ± 206 vs. 241 ± 216 min/wk] compared with those who did not obtain 7 hours of sleep per night. CONCLUSION:Soldiers who choose to adopt healthy lifestyle characteristics may be more likely to meet the recommended sleep duration guideline.

The Department of Defense is the largest employer of full-time musicians. In the U.S. military, many musicians experience unique occupational exposures such as extended periods of standing, sitting, and marching for rehearsals and performances, static and non-neutral postures, and a variety of repetitive motions while playing instruments. These exposures are in addition to physical training and fitness standards required of U.S. Army soldiers.METHODS:An electronic survey was administered to active-duty U.S. Army Band musicians. The survey collected demographics, personal characteristics, Army Physical Fitness Test performance, occupational demands, health behaviors, and injuries from October 2017 to December 2018. Survey responses were combined with medical and physical fitness performance records. Descriptive statistics were reported and factors associated with injuries were investigated.RESULTS:There were 465 Army Band members in this population, with approximately half (49%) completing the survey. Most survey respondents (81%) reported an injury in the past year, which they predominantly attributed to overuse (54%). Leading reported activities resulting in injury included running for physical training (21%), repetitive movements while playing an instrument (11%), and standing while playing (11%). A majority of survey respondents (60%) also had a medical encounter for an injury. Factors significantly associated with injury among men were lower aerobic fitness and higher body fat percentage; additional unadjusted factors associated with injury among all Army Band soldiers included female sex, older age, and longer periods of marching and standing while playing.CONCLUSIONS:Injury prevention initiatives for Army Band musicians should focus on the reduction of overuse and repetitive motion injuries. Suggested prevention strategies include balanced physical training, ergonomic adjustments, rehearsal breaks, and leadership support for injury prevention efforts.

U.S. Army Ranger School is an arduous 64-day leadership training course designed to simulate the stressors of combat. Although physical fitness has been shown to be an important predictor of successful graduation for Ranger School, psychosocial characteristics like self-efficacy and grit have not been examined. The purpose of this study is to identify personal, psychosocial, and fitness characteristics associated with successful completion of Ranger School. This study was a prospective cohort examining the association of baseline characteristics of Ranger School candidates with a primary outcome of graduation success. Multiple logistic regression was performed to determine the contribution of demographics, psychosocial, fitness and training characteristics to graduation success. Out of 958 eligible Ranger Candidates, this study obtained graduation status for 670 students, 270 (40%) of which graduated. Soldiers who graduated were younger, more likely to come from units with a higher proportion of previous Ranger School graduates, had higher self-efficacy and faster 2-mile run times. The results from this study suggest that Ranger students should arrive in optimal physical conditioning. Furthermore, training programs that optimize student self-efficacy and units with a high proportion of successful Ranger graduates may confer advantage for this challenging leadership course.

Introduction Multiple studies report increasing cases of surgically treated pectoralis major (PM) muscle and tendon ruptures in military populations. Studies associate this with a growing popularity of weight-training and bench press exercises. Mild-to-moderate non-surgical PM traumas and overuse injuries have not been included in these studies despite evidence that these types of outpatient injuries account for the majority of the military’s injury medical burden. Methods To assess rates of all PM injuries (ruptures, tears, strains, overuse), regardless of form of treatment, a PM injury surveillance definition was derived from International Classification of Disease (ICD) diagnostic codes used in routine US Army injury surveillance. A detailed clinical examination of 2016 Active Duty Army medical records was used to identify ICD codes commonly associated with PM injuries. Cost data were calculated and the definition applied to medical data from 2016 through 2018to assess trends. Results The estimated incidence of PM cases among soldiers was over 95% greater than if only considering severe surgical cases. Over 96% of army annual PM injury costs (direct medical and indirect from lost labour) were for outpatient services. PM injury incidence rates were not statistically different from 2016 to 2018. Conclusions The PM injury surveillance definition provides a consistent means to monitor trends over time and evaluate the effectiveness of prevention efforts. PM injuries have a larger military impact than previously recognised and prioritised prevention strategies are needed to reduce them. Future interventions could focus on the bench press given its observed association with PM injuries.

The estimated cost to the Army for lower extremity fractures in 2017 was approximately $116 million. Direct medical expenses totaled $24 million, and indirect medical costs totaled $92 million ($900 thousand lost duty; $91 million limited duty). Foot and toe fractures, along with lower leg and ankle fractures accounted for the majority of soldiers' initial visits for care (n=4,482; 91.6%), and more than $103 million (89.0%) of overall costs ($116 million). Costs varied by location of care. In outpatient settings, initial visits for foot and toe injuries accounted for the highest costs: $49 million overall. Direct medical costs totaled $1.2 million, and indirect medical costs (limited duty) were $48 million. Conversely, in inpatient settings, lower leg and ankle fractures accounted for slightly more than half of all costs (overall $9 million; $4.8 million in direct medical costs and $4.5 million in indirect medical costs). The finding that the majority of costs related to lower extremity fractures were due to estimated days of lost or limited duty and associated loss of productivity justifies the inclusion of indirect cost estimates as a part of overall injury cost calculations.

Abstract Alemany, JA, Pierce, JR, Bornstein, DB, Grier, TL, Jones, BH, and Glover, SH. Comprehensive physical activity assessment during U.S. Army Basic Combat Training. J Strength Cond Res 36(12): 3505–3512, 2022—Physical activity (PA) volume, intensity, and qualitative contextual information regarding activity type and loads carried are limited during U.S. Army Basic Combat Training (BCT). The purpose of this study was to characterize daily (05:00–20:00 hours) PA during BCT using a comprehensive approach. During 2 10-week BCT cycles (n = 40 trainees per cycle), pedometers, accelerometers, and direct observation were used to estimate daily step count, PA volume, and intensity. Physical activity intensity was categorized by metabolic equivalents (METs) such as “sedentary” (1–2 METs), “light” (2–3 METs), “moderate” (3–6 METs), or “vigorous” (≥6 METs). Daily PA data were analyzed longitudinally using linear mixed models, with significance set at p ≤ 0.05. The mean daily step count was 13,459 ± 4,376 steps, and the mean daily accelerometer-assessed PA volume and intensity were as follows: sedentary: 505 ± 98 minutes, light: 190 ± 78 minutes, moderate: 168 ± 51 minutes, and vigorous: 14 ± 14 minutes, with no differences between cycles for all measures (p > 0.50). Cumulative time on feet (∼50%) and sitting (20–25%) accounted for most daily activity types during both cycles. Trainees, on average, carried between 3 and 9 kg, and ≥9 kg, for 60% and 10% of the monitored day, respectively. Basic Combat Training's physical demands are high, where trainees achieved 1.7 to 2.7 times greater daily ambulation and 6 times the recommended weekly moderate-to-vigorous PA compared with civilian counterparts and performed weight-bearing load carriage for nearly half of the day. Basic Combat Training-associated PA may increase injury risk among trainees unaccustomed to arduous PA and exercise. Implementing national PA policies to improve physical fitness and facilitate acclimatization to BCT's high physical demands could reduce public health burdens and military nonreadiness.

The goals of this project were to quantify medical problems among a population of Military Working Dogs (MWDs) and analyze factors associated with common medical conditions. Medical conditions recorded in veterinary Master Problem List (MPL) entries for 774 young, non-deployed, active MWDs were categorized and combined with demographic information to analyze risk factors. Most dogs were male (74%), German Shepherd (39%) or Belgian Malinois (31%) breeds, certified in Explosive Detection (60%), and had a dark coat color (83%). Ages ranged from one to six years, with an average of 2.6 years (± 0.5 years). Eighty-three percent of dogs had a non-surgical medical problem in their record. The most common non-surgical medical problems were dermatologic (25% of MPL entries), alimentary (21%), dental (15%), soft-tissue injury (10%), and musculoskeletal conditions (4%). Factors associated with each medical condition were breed (Odds Ratios 1.96-8.24), sex and spay/neuter status (ORs 1.78-5.77), occupational duty certification (ORs 2.65-3.62), military command location (ORs 2.32-7.44), and military branch (OR 5.16). As MWDs are a valuable asset for the Department of Defense, training and work conditions for the identified at-risk groups of MWDs should be further assessed to maximize their operational capabilities and assess the potential to serve as sentinel indicators for human diseases. Improved understanding of the most common medical problems affecting MWDs, and the identification of factors associated with these conditions, can help drive changes in their preventive care.

Abstract Grier, T, Brooks, RD, Solomon, Z, and Jones, BH. Injury risk factors associated with weight training. J Strength Cond Res 36(2): e24–e30, 2022—The purpose of this evaluation was to identify injury risk factors associated with weight training (WT). Subjects were 4,785 men and 542 women in a U.S. Army Division. Personal characteristics, unit training, personal training, fitness, and 12-month injury history were obtained by an electronic survey. Risk factors for WT injuries were explored using backward stepping multivariable logistic regression. Risk ratios, odds ratios (ORs), and 95% confidence intervals (95% CIs) were calculated for each risk factor. Over a one-year period, 4.5% of men and 0.6% of women experienced a WT injury. Weight-training injury incidence was 0.31 and 0.05 per 1,000 hours of WT for men and women, respectively. Overall, men were 7.4 times more likely to experience a WT injury compared with women. For men who participated in WT, independent risk factors for a WT injury included older age (OR [23–27/≤ 22 years] = 1.99, 95% CI 1.22–3.27; OR [>28/≤ 22 years] = 2.48, 95% CI 1.52–4.03) and higher amounts of personal WT per week (OR [60–165/≥ 166 minutes] = 0.58, 95% CI 0.39–0.88; and OR [15–59/≥ 166 minutes] = 0.40, 95% CI 0.24–0.66). A linear trend was revealed indicating an increasing risk of a WT injury with greater amounts of time spent WT per week (p < 0.01). Performing moderate amounts of WT may reduce the risk of experiencing a WT injury. However, because muscle strength is an important component of fitness for Soldiers, specialized WT programs that improve strength while minimizing injury risks are needed.

Purpose: In physically demanding occupations or athletic populations, sleep has been shown to be an important factor for both performance and recovery. However, evidence is limited on sleep duration and its assodation with musculoskeletal injury risk in physically active populations. Therefore, the purpose of this analysis was to evaluate the relationship between sleep duration and musculoskeletal injury incidence in a population of physically active men and women. Methods: Data were collected via electronic survey and analyzed for 7,576 soldiers from the United States Army Special Operations Command. Results: This population was mostly men (95%) <= 35 years old (70%). The incidence of musculoskeletal injury was 53% over the twelve months before survey administration. After adjusting for other covariates, soldiers who slept <= 4 hours were 2.35 (95% Cl. 1.89-2.93, p < 0.01) times more likely to experience a musculoskeletal injury compared with those who slept eight >= 8 hours. When stratified by age (<= 35 years, > 35 years), older men were found to have significantly higher risk of a musculoskeletal injury than their younger counterparts across all sleep duration groups. Conclusions: These findings suggest that sleep duration may be inversely related to risk of musculoskeletal injury. It is possible that interventions targeted at sleep may have a positive impact on prevention of musculoskeletal injuries within physically active populations. (C) 2020 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

There is limited literature concerning the types of injuries that military working dogs (MWDs) face while in a deployed theater of operations and associated risk factors. To summarize injuries and identify injury risk factors in MWDs during their first deployments to Iraq, demographic and medical data were collected for 794 MWDs from the U.S. Army, Air Force, Navy, and Marine Corps that deployed to Iraq between March 20, 2003 and December 31, 2007. Sixty-two percent (n = 490) had a medical encounter during deployment. Injuries were categorized as traumatic or musculoskeletal. MWD demographics, characteristics, and injury types were summarized. Injury risk factors were assessed using multivariable logistic regression. A majority of the population were German Shepherds (56 %), intact males (49 %), and dogs certified in both patrol and explosives detection (73 %). During their first deployment to Iraq, 20 % (n = 156) experienced an injury. Risk factors included breed, age, and occupational certification. Belgian Malinois and Labrador Retriever dogs had greater odds of injury compared to German Shepherds (p = 0.04 and p = 0.02) and the oldest MWDs had about a 50 % higher risk of injury compared to the youngest (p = 0.01), especially for musculoskeletal injuries. MWDs with Specialized Search certification were at increased injury risk (p = 0.02). Training, equipment, and supplies for veterinary service personnel, MWD handlers, and MWDs should be tailored with consideration of the injury risks of the MWD population. Further study is needed to investigate chronic injuries in military working dogs to better understand causation and prevention.

Injuries are a leading health and readiness concern for the US Army. For effective prevention planning, details concerning circumstances associated with injuries are needed. Over 5,000 Soldiers were surveyed to collect demographic and injury details (type, body part, mechanism, activity, limited duty days); 874 reported an injury within 6 months of survey administration. The greatest proportion of limited duty time was associated with knee (19.2%), ankle (14.8%), and lower back injuries (12.9%). Overexertion was the leading injury mechanism (43.9%), followed by falls, jumps, trips, and slips (35.2%), which accounted for the highest average limited duty days per injury (42±43 days). Running was the leading activity associated overexertion injuries (39.3%) and falls (30.5%). Running also accounted for the greatest total limited duty days (5,844 days, 29.8%). For Army infantry units, results suggested a focus of prevention activities on running-related injuries resulting in overexertion or falls. Healthcare providers can facilitate injury prevention with contributions to initiatives providing details on injury mechanisms and activities associated with injuries.

Objectives: The objectives of the study are to quantify the proportion of cumulative microtraumatic overuse injuries in a physically active population, evaluate their impact in terms of lost work time, and link them to precipitating activities to inform prevention initiatives. Study design: The study design is retrospective cohort study. Methods: For a population of U.S. Army Soldiers, diagnoses from medical records (International Classification of Diseases [ICD]-9 800-999 and selected ICD-9 710-739) were matched with self-reported injury information. Common diagnoses, limited duty days, and activities and mechanisms associated with the injuries were summarized. Results: Most self-reported injuries (65%) were classified by providers with diagnoses that described cumulative microtraumatic tissue damage, and these injuries led to a higher incidence of limited duty (85%) than acute traumatic injury diagnoses. Reported mechanisms and activities often indicated repetitive physical training-related onset. Conclusions: Because many diagnoses for cumulative microtraumatic musculoskeletal tissue damage are categorized as diseases to the musculoskeletal system in the International Classification of Diseases, they are often not included in definitions of injury. However, reported injury activities and mechanisms in this population provide evidence that cumulative microtraumatic injuries often arise from identifiable and preventable events. This finding confirms that these diagnoses should be classified as injuries in epidemiologic evaluations and surveillance to accurately represent injury burden. Published by Elsevier Ltd on behalf of The Royal Society for Public Health.

•Less than half of individuals with a medically documented injury report it.•Accurately estimating injury rates requires data from multiple sources.•Survey data should be used in combination with, not in lieu of, medical records.