Ad libitum caffeine consumption, cognitive performance, and sleep in special forces soldiers during a 96-h combat exercise.

Introduction: This observational study investigated the effects of sleep deprivation and ad libitum caffeine consumption on cognitive performance, risk behavior, and mood among 28 Israeli Special Forces (SF) soldiers (mean age: 20.57 ± 0.92 years) during a 96-hour combat exercise. Methods: Actigraphy was used to monitor sleep and activity; cognitive function, risk-taking propensity, mood states, and self-reported sleepiness were assessed using the Psychomotor Vigilance Task (PVT), Evaluation of Risks Scale (EVAR), Profile of Mood States (POMS), Karolinska Sleepiness Scale (KSS); and caffeine consumption by questionnaire at 0, 50, and 96 hours. For analyses, participants were divided into Low (<400 mg) and High (≥400 mg) caffeine consumption groups. Results: The soldiers hiked 108.5 ± 0.52 km and slept for 12.7 ± 0.5 h, with a notable transition from multiple short sleep epochs in the initial 50 hours to a consolidated 5-hour sleep period subsequently. In the High caffeine group, PVT reaction time was faster (p = 0.024) compared to the Low caffeine group, with fewer premature response errors (p = 0.026). However, this group showed increased risk-taking (p = 0.037), particularly reduced Self-Control (p = 0.010). No significant impact of ad libitum caffeine intake on mood was observed. However, degradation over the course of the exercise in both groups in mood states, including anger, fatigue, tension, and vigor, was noted (p < 0.05). KSS scores increased significantly at 50 and 96 h (p < 0.001). Discussion: These results suggest that while caffeine enhances cognitive function, its ad libitum consumption did not consistently improve these measures in this cohort of SF soldiers. The study highlights the complex relationship between sleep deprivation and caffeine intake and their combined effects on soldiers' cognitive and behavioral functions, indicating a need for evidence-based caffeine use guidelines for using caffeine in military settings.

Drowning rates among children and adolescents (aged 7-17) in Israel during the years 2008-2018.

OBJECTIVE: Drowning is one of the leading causes of death among children and youth worldwide. This study aims to examine differences in the rates of drowning (fatal and non-fatal drowning) among children and youth in Israel stratified by age, sex, sector, place of drowning, and the drowning outcome. In addition, we compared the results of studies reported in other countries in specific age groups based on statistics of about 100,000 drowning cases. METHOD: A statistical analysis of 474 drownings between 2008 and 2018 was conducted. All cases refer to youngsters aged 7-17 in the State of Israel. Statistical analysis was performed on data obtained from the Beterem - Safe Kids Israel organization and from the Israel Central Bureau of Statistics. Disparities between groups within the examined population were analyzed based on gender, sector (Jewish versus non-Jewish), and drowning site. RESULTS: Of the 474 drownings that occurred during 2008-2018, 38.4% ended in death. 79% of the cases occurred in pools. The Arab minority sector (21.1% of the general population) accounted for 25.1% of all drownings, males accounted for 70.5% of the drowning cases, and the age group with the most drownings (48.5%) was that of 15-17 years. The Jewish population was involved in more than 75% of drownings in places designated for bathing and in more than 83% of all disaster scenarios, whereas the Arab minority was involved in more than 61% of drownings in places not designated for bathing. CONCLUSIONS: The results are comparable to those of other studies worldwide. Boys drown twice as much as girls, mainly in the age group of 15-17. This may be explained by overconfidence in boys and a tendency to overestimate their actual swimming abilities. Most drownings occur in pools. Drowning among the Jewish population occurs mainly in designated bathing sites. PRACTICAL APPLICATIONS: The findings can and, in fact, must be used to inform and educate the younger generation as to the potential dangers involving bathing in designated bathing sites.

Beating the heat: military training and operations in the era of global warming.

Global climate change has resulted in an increase in the number and intensity of environmental heat waves, both in areas traditionally associated with hot temperatures and in areas where heat waves did not previously occur. For military communities around the world, these changes pose progressively increasing risks of heat-related illnesses and interference with training sessions. This is a significant and persistent "noncombat threat" to both training and operational activities of military personnel. In addition to these important health and safety concerns, there are broader implications in terms of the ability of worldwide security forces to effectively do their job (particularly in areas that historically already have high ambient temperatures). In the present review, we attempt to quantify the impact of climate change on various aspects of military training and performance. We also summarize ongoing research efforts designed to minimize and/or prevent heat injuries and illness. In terms of future approaches, we propose the need to "think outside the box" for a more effective training/schedule paradigm. One approach may be to investigate potential impacts of a reversal of sleep-wake cycles during basic training during the hot months of the year, to minimize the usual increase in heat-related injuries, and to enhance the capacity for physical training and combat performance. Regardless of which approaches are taken, a central feature of successful present and future interventions will be that they are rigorously tested using integrative physiological approaches.

Hand Grip Strength Relative to Waist Circumference as a Means to Identify Men and Women Possessing Intact Mobility in a Cohort of Older Adults with Type 2 Diabetes.

Possessing intact mobility in older adults assures their continued independence. The early identification of reduced mobility in older adults with type 2 diabetes (T2DM) is paramount for preventing their future physical deterioration. Hand grip strength (HGS), relative to body size, is associated with mobility in older T2DM patients. This study aims to identify an HGS index that best identifies mobilityintact older T2DM patients, along with its optimal cut-off point. The baseline data are from a cohort of 122 older T2DM patients (59% women) (mean age of 70.2 ± 4.4 years). Three mobility tests encompassing three main mobility domains were measured, including usual gait speed (UGS), timed up and go (TUG), and a two-minute walk test (2MWT). Passing scores were defined as those either above the established cut-off points or above the 25th percentile of population norms. Passing all three tests was considered as possessing intact mobility. Receiver operating characteristic (ROC) curves of the most relevant HGS indices were constructed to determine the area under the curve (AUC) that best identifies patients with intact mobility. In a sample of 122 older adults with T2DM, 63.9% of women and 60% of men were found to possess intact mobility. HGS relative to waist circumference (WC) was found to have the strongest association with intact mobility, presenting the highest AUC in both men (0.78) and women (0.72) for discriminating mobility status, with an optimal cut-off of 0.355 (kg/cm) and 0.245 (kg/cm) in men and women, respectively. HGS relative to WC best differentiated between mobility-intact older adults with T2DM and those with mobility limitations, especially in men. Using HGS/WC as a simple and safe screening mode for mobility in a clinical setting could potentially identify older patients with T2DM that require therapeutic interventions.

Transitional Care Management Quality Improvement Methods That Reduced Readmissions in a Rural, Primary Care System.

BACKGROUND: Transitional Care Management (TCM) is a reimbursable service designed to minimize hospital readmissions. We describe a multifaceted approach to increase TCM services among 107 primary care providers in a rural catchment area of 4250 square miles. OBJECTIVE: The primary objective was to increase use of TCM phone calls, office visits, and billing codes; the secondary objective was to decrease hospital readmissions. METHODS: We utilized a learning health system model, an improvement support team (IST), and a learning collaborative that included webinars and in-person support. The process emphasized user-centered system redesign, coaching, electronic health record (EHR) improvements, and real-time feedback. Analyses included statistical process control charts, box plots, analysis of variance, and t-tests. RESULTS: The IST engaged stakeholders to design and test TCM workflows and EHR prototypes. This resulted in rapid, iterative improvements and system-wide spread of new processes. In the month following implementation, TCM calls and visits quadrupled and increased during 18 subsequent months. Pragmatically, most discharged patients (95% in a subsample) did not receive both the TCM call and visit, serving as a comparison group. The Readmission rate for patients receiving complete TCM services was 5.0% (n = 101) versus 11.9% for comparators (n = 2103, P = .03). Billing codes increased initially, then returned to baseline. CONCLUSIONS: Our approach led to rapid, sustained scaling of TCM calls and visits in a rural primary care group. Patients who received TCM calls and visits had significantly fewer readmissions. Training of new staff, including PCPs, is required for sustainability. Future research is warranted to increase adoption and evaluate additional outcomes including mortality rates, patient satisfaction, and health care economics.

Should knee extension strength testing be implemented as a screening test for identifying probable and confirmed sarcopenia in older T2DM patients?

BACKGROUND: The accelerated loss of muscle strength and mass observed in older type 2 diabetes mellitus (T2DM) patients due to the combined effects of diabetes and obesity, greatly increases their risk for sarcopenia. Early detection and treatment of probable and confirmed sarcopenia is paramount to delay mobility disability. Using low handgrip strength cut-off points for the initial identification of sarcopenia according to the new European Working Group on Sarcopenia in Older People (EWGSOP2) guidelines may mask the presence of sarcopenia. Relative knee extension strength cut-off points using a simple hand-held dynamometer can assist clinicians in the diagnosis of probable and confirmed sarcopenia by possibly reducing false negative results. METHODS: A cohort of one hundred T2DM older patients (60% women) (mean age 74.5 years) mostly obese community dwelling older adults were evaluated for body composition by Bioelectrical impedance analysis (BIA), yielding appendicular skeletal mass index (ASMI) results. Patients underwent handgrip strength (HGS) and knee extension strength (KES) tests as well as functional ability tests. Prevalence of probable and confirmed sarcopenia using HGS and KES cut-off points were calculated. Pearson correlations were performed to evaluate the relationship between ASMI and limbs strength. A regression analysis was conducted to examine which variables best predict ASMI values. A multivariate analysis of covariance was performed to assess the effect of independent variables on KES and HGS. RESULTS: Using cutoff points for low KES identified 24 patients with probable sarcopenia and two with confirmed sarcopenia. Conversely, using the EWGSOP2 cut off points for low HGS, identified only one patient with probable sarcopenia and none of the patients with confirmed sarcopenia. CONCLUSION: KES cut-off points using a simple hand-held dynamometer can assist in the identification of probable and confirmed sarcopenia using EWGSOP2 cut off points for low muscle mass in a population of older T2DM patients for further analysis and early treatment. This is notably true in patients possessing high body mass index (BMI) alongside normal ASMI and HGS, potentially reducing false positive sarcopenia screening results. TRIAL REGISTRATION: ClinicalTrials.gov PRS: NCT03560375 . Last registration date (last update): 06/06/2018. The trial was a-priori registered before actual recruitment of subjects.

Social Capital as a Mediator in the Link between Women's Participation in Team Sports and Health-Related Outcomes.

The role of social capital in the association between team sports and health-related outcomes has not been well established in the literature. The purpose of this study was to explore whether social capital components (social support, trust, and social involvement) mediate the association between team sports and health-related outcomes (self-reported health, psychosomatic symptoms, and depressive symptoms). In a cross-sectional research design, we obtained data from 759 participants in the Mamanet Cachibol League, a community team sports model for women in Israel, as well as a comparison group of 308 women who did not participate in any team sports. Team captains were sent a link with an online questionnaire, which were then delivered to team members via text message. Using three parallel mediation models, we found that social support mediated the association between team sports and self-reported health, psychosomatic symptoms, and depressive symptoms. Trust mediated the association between team sports and both psychosomatic symptoms and depressive symptoms. Social involvement was not found to be a mediator in the association between team sports and any of the health-related outcomes. Our findings reveal the important role of social capital, specifically social support and trust, in promoting the health of women who participate in team sports.

Ethnic Disparities in Social Capital and Health among Jewish and Arab Participants in the Israeli Mamanet Cachibol League.

The Israeli Mamanet Cachibol League (MCL) serves as a community model that incorporates physical activity and amateur team sports among women. Team sports have been shown to bridge gaps and build positive relationships between communities. There is a paucity of data regarding the advantages of team sports to promote the health and well-being of women from different ethnic backgrounds. The purpose of this study was to examine the association of participation in MCL with social capital, health, and well-being across two ethnic groups: Jewish and Arab women. A cross-sectional survey was conducted among women aged 25-64: 102 Jewish and 96 Arab MCL participants, and 102 Jewish and 81 Arab non-MCL participants. Data regarding social capital (trust, social support and social involvement) and well-being (self-reported health and psychosomatic and depressive symptoms) were analyzed using two-way analyses of covariance and multiple regression models with sequential entry of the variables. MCL participants from both ethnic groups reported higher social capital (p < 0.001), better self-reported health (p < 0.001), and lower psychosomatic symptoms (p < 0.001) compared to non-participants. Jewish MCL participants reported lower depressive symptoms (p < 0.001) than non-participants, however no difference was found between Arab MCL participants and non-participants (p < 0.160). Amateur team sports such as MCL are related with higher levels of well-being and social capital. Future research should focus on longitudinal studies that examine the change in social capital and well-being over time.

Minimally supervised home-based resistance training and muscle function in older adults: A meta-analysis.

In an attempt to define feasible means to improve compliance with current recommendations on resistance training in older subjects, published evidence on the efficacy and safety of minimally supervised home-based resistance training (MSHBRT) on muscle strength and functionality was systematically evaluated in this population segment for the first time. We performed a meta-analysis using the following data sources: MEDLINE (Ovid), EMBASE and Cochrane, with a total of 1160 subjects with a mean age of 72 ±â€¯6.3 years. MSHBRT modestly increased lower body strength (MD 0.6 Kg, 95% CI, 0.16-1.04) in a diverse population of older adults including subjects with significant age-related diseases. Although earlier evidence indicates that larger increments in muscle performance and function can be attained through more intense and directly supervised resistance training, MSHBRT may comprise a useful and inexpensive method to preserve and even enhance lower body muscle strength in older adults.

Fire Disaster Readiness: Preparation for the Evacuation of Medical Facilities During Fires in Haifa, Israel, 2016.

When a fire occurs, there is little time to escape. In less than 30 seconds, a fire can rage out of control, filling the area with heat and toxic thick smoke (Purdue University Fire Department, 2017; http://www.purdue.edu/ehps/fire/fire-101.html.) In 2010, following the successful evacuation of Maale Ha'Carmel Mental Health Center during a raging forest fire in the area, a comprehensive investigation was performed to evaluate the management of the evacuation process and to systematically elicit lessons learned from the incident. In 2016, a forest fire erupted in the same geographic area that required the evacuation of Fliman Geriatric Rehabilitation Hospital, and methodical debriefing identified the strengths and weaknesses of the evacuation process in that hospital. The lessons learned from the evacuation of these two health care facilities, which were at the focus of major fires in Israel in 2010 and in 2016, are presented. (Disaster Med Public Health Preparedness. 2019;13:375-379).

[SOCIAL IMPACT BONDS FOR HEALTH PROMOTION AND PREVENTIVE MEDICINE].

INTRODUCTION: The World Health Organization (WHO) has declared obesity a global epidemic. WHO sheds much light on this matter in its publications on health promotion and preventative medicine. Lack of physical activity, an unbalanced diet and an unhealthy lifestyle are the leading causes of developing obesity and chronic diseases. In Israel, the growing rate of obesity is a reason for concern. About 500,000 diabetics, mainly as a result of obesity, live in Israel today and by 2030 the number is expected to rise to 2,000,000. Every third child born is expected to develop diabetes by the time they reach the age of 40 unless a profound change is made in health policy. The State of Israel recognizes its responsibility in promoting awareness against obesity as well as its role in prevention. In spite of the country's recognition of the problem, it still has not managed to implement long term solutions which address the issue. Therefore, creative and innovative solutions are called for. The social impact bond (SIB), a newly developed financial model is a possible solution. This model suggests the entry of private investors into the public sector, a field which is within the responsibility of the government. The private investor will be in charge of running a social program on a topic which will be finalized with the government. The private investor and the government will have a contract outlining the program and the criteria for the evaluation and the success of the program. To note, the private investor will only be paid according to the success of the program. Thus the purpose of SIB is in motion processes and is set to serve as a model for several years, and then the authorities will take over the responsibility and continue with the program that the SIB handled. In March 2016, a new SIB was launched in Israel to prevent Type 2 diabetes. This involves 2250 pre-diabetic adults who are at risk to develop Type 2 diabetes and will be identified by their Health Maintenance Organizations (HMOs, Clalit and Leumit) through blood tests. The participants will take part in an intensive intervention wellness program during 3 years. This SIB aims to prevent the onset of diabetes. If successful, and a significant reduction in Type 2 diabetes is found, there will be substantial savings for the HMOs and the National Insurance Institute, which will in turn repay the investors for their expenses, according to the signed contract. This SIB will serve as a pilot project for diabetes prevention and if successful, this model can be adopted for other projects in preventive medicine and health promotion. Thereby, we may be facing a dramatic change in the paradigm of funding national health services in Israel.

Effect of cardiovascular and muscular endurance is not associated with stress fracture incidence in female military recruits: a 12-month follow up study.

BACKGROUND: Stress fracture (SF) is a common injury among military recruits, especially among women, during the army basic training (ABT). The purpose of this study was to evaluate the effects of health habits and physical activity before recruitment on the fitness level and the incidence of SF during the 4-month ABT. METHODS: We screened 226 female recruit volunteers (weight: 60.5±10 kg; height: 163±6 cm) from an integrated combat unit and 124 aged-matched female controls (weight: 57.0±8.3 kg, height 162±7 cm) from a non-combat unit. A self-report questionnaire on their habits pertaining to smoking, physical activity, and orthopedic injuries prior to recruitment were analyzed in relation to the incidences of SF during ABT. RESULTS: Aerobic fitness was similar between the two groups. The overall incidence of SFs was 10.2%. Physical training prior to recruitment had no significant effect on the incidence of SF during ABT (11.7% vs. 9.6% in those who trained and did not train before recruitment, respectively) (Odds ratio, OR)=1.24, p=0.236). Nearly 42% of the female recruits smoked regularly, and the incidence of SFs among smokers was 10.5% compared with 9.9% among the non-smokers (OR=1.07, p=0.188). The overall incidence of SFs 12 months after recruitment was 1.78%. The use of contraceptive medication did not affect the incidence of SF: 10.0% among prior-trained vs. 6.4% in non-prior trained (p>0.05) recruits. SFs were not correlated to these variables at the end of the ABT program and 16 months after recruitment. CONCLUSIONS: In the present female cohort, physical activity prior to recruitment had no protective effect against SF during or after ABT. The incidence of SFs during the 12-month period after ABT was negligible.

Functional polymorphisms in the P2X7 receptor gene are associated with stress fracture injury.

Military recruits and elite athletes are susceptible to stress fracture injuries. Genetic predisposition has been postulated to have a role in their development. The P2X7 receptor (P2X7R) gene, a key regulator of bone remodelling, is a genetic candidate that may contribute to stress fracture predisposition. The aim of this study is to evaluate the putative contribution of P2X7R to stress fracture injury in two separate cohorts, military personnel and elite athletes. In 210 Israeli Defense Forces (IDF) military conscripts, stress fracture injury was diagnosed (n = 43) based on symptoms and a positive bone scan. In a separate cohort of 518 elite athletes, self-reported medical imaging scan-certified stress fracture injuries were recorded (n = 125). Non-stress fracture controls were identified from these cohorts who had a normal bone scan or no history or symptoms of stress fracture injury. Study participants were genotyped for functional SNPs within the P2X7R gene using proprietary fluorescence-based competitive allele-specific PCR assay. Pearson's chi-squared (χ (2)) tests, corrected for multiple comparisons, were used to assess associations in genotype frequencies. The variant allele of P2X7R SNP rs3751143 (Glu496Ala-loss of function) was associated with stress fracture injury, whilst the variant allele of rs1718119 (Ala348Thr-gain of function) was associated with a reduced occurrence of stress fracture injury in military conscripts (P < 0.05). The association of the variant allele of rs3751143 with stress fractures was replicated in elite athletes (P < 0.05), whereas the variant allele of rs1718119 was also associated with reduced multiple stress fracture cases in elite athletes (P < 0.05). The association between independent P2X7R polymorphisms with stress fracture prevalence supports the role of a genetic predisposition in the development of stress fracture injury.

Critical Velocity Is Associated With Combat-Specific Performance Measures in a Special Forces Unit.

The purpose of this study was to examine the relationship between critical velocity (CV) and anaerobic distance capacity (ADC) to combat-specific tasks (CST) in a special forces (SFs) unit. Eighteen male soldiers (mean ± SD; age: 19.9 ± 0.8 years; height: 177.6 ± 6.6 cm; body mass: 74.1 ± 5.8 kg; body mass index [BMI]: 23.52 ± 1.63) from an SF unit of the Israel Defense Forces volunteered to complete a 3-minute all-out run along with CST (2.5-km run, 50-m casualty carry, and 30-m repeated sprints with "rush" shooting [RPTDS]). Estimates of CV and ADC from the 3-minute all-out run were determined from data downloaded from a global position system device worn by each soldier, with CV calculated as the average velocity of the final 30 seconds of the run and ADC as the velocity-time integral above CV. Critical velocity exhibited significant negative correlations with the 2.5-km run time (r = -0.62, p < 0.01) and RPTDS time (r = -0.71, p < 0.01). In addition, CV was positively correlated with the average velocity during the 2.5-km run (r = 0.64, p < 0.01). Stepwise regression identified CV as the most significant performance measure associated with the 2.5-km run time, whereas BMI and CV measures were significant predictors of RPTDS time (R(2) = 0.67, p ≤ 0.05). Using the 3-minute all-out run as a testing measurement in combat, personnel may offer a more efficient and simpler way in assessing both aerobic and anaerobic capabilities (CV and ADC) within a relatively large sample.

ß-Alanine supplementation and military performance.

During sustained high-intensity military training or simulated combat exercises, significant decreases in physical performance measures are often seen. The use of dietary supplements is becoming increasingly popular among military personnel, with more than half of the US soldiers deployed or garrisoned reported to using dietary supplements. ß-Alanine is a popular supplement used primarily by strength and power athletes to enhance performance, as well as training aimed at improving muscle growth, strength and power. However, there is limited research examining the efficacy of ß-alanine in soldiers conducting operationally relevant tasks. The gains brought about by ß-alanine use by selected competitive athletes appears to be relevant also for certain physiological demands common to military personnel during part of their training program. Medical and health personnel within the military are expected to extrapolate and implement relevant knowledge and doctrine from research performed on other population groups. The evidence supporting the use of ß-alanine in competitive and recreational athletic populations suggests that similar benefits would also be observed among tactical athletes. However, recent studies in military personnel have provided direct evidence supporting the use of ß-alanine supplementation for enhancing combat-specific performance. This appears to be most relevant for high-intensity activities lasting 60-300 s. Further, limited evidence has recently been presented suggesting that ß-alanine supplementation may enhance cognitive function and promote resiliency during highly stressful situations.

Physiological and cognitive military related performances after 10-kilometer march.

BACKGROUND: Prior operational activities such as marching in diverse environments, with heavy backloads may cause early fatigue and reduce the unit's readiness. The purpose of this preliminary study was to evaluate the effect of 10-kilometer (km) march on selected, military oriented, physiological and cognitive performances. Eight healthy young males (age 25 ± 3 years) performed a series of cognitive and physiological tests, first without any prior physiological strain and then after a 10 km march in comfort laboratory conditions (24°C, 50%RH) consisting a 5 km/h speed and 2-6% incline with backload weighing 30% of their body weight. RESULTS: We found that the subjects' time to exhaustion (TTE) after the march decreased by 27% with no changes in anaerobic performance. Cognitive performance showed a significant (20%) reduction in accuracy and a tendency to reduce reaction time after the march. CONCLUSIONS: We conclude that a moderate-intensity march under relatively comfort environmental conditions may differently decrease selected military related physical and cognitive abilities. This phenomenon is probably associated with the type and intensity of the pre-mission physical activity and the magnitude of the associated mental fatigue. We suggest that quantifying these effects, as was presented in this preliminary study, by adopting this practical scientific approach would assist in preserving the soldiers' performance and health during training and military operations.

ß-Alanine ingestion increases muscle carnosine content and combat specific performance in soldiers.

The purpose of this study was to examine the effect of ß-alanine (BA) ingestion on tissue carnosine levels and the impact such changes would have on combat specific activity. Eighteen soldiers (19.9 ± 0.8 year) from an elite combat unit were randomly assigned to either a BA or placebo (PL) group. Before and following a 30-day supplementation period carnosine content of the gastrocnemius muscle and brain was determined by proton magnetic resonance spectroscopy. During each testing session, participants performed military relevant tasks that included a 2.5 km run, a 1-min sprint, 50-m casualty carry, repeated 30-m sprints with target shooting, and a 2-min serial subtraction test (SST) to assess cognitive function under stressful conditions. A significant elevation (p = 0.048) in muscle carnosine content was noted in BA compared to PL. Changes in muscle carnosine content was correlated to changes in fatigue rate (r = 0.633, p = 0.06). No changes (p = 0.607) were observed in brain carnosine content. Following supplementation, no differences were noted in 2.5 km run, 1-min sprint, repeated sprint, or marksmanship performance, but participants in BA significantly (p = 0.044) improved their time for the 50-m casualty carry and increased their performance (p = 0.022) in the SST compared to PL. In summary, 30-days of BA ingestion can increase muscle carnosine content and improve aspects of military specific performance. Although cognitive performance was significantly greater in participants consuming BA compared to placebo, current study methods were unable to detect any change in brain carnosine levels, thus, the precise mechanism underlying these effects remains elusive.

Evaluation of the performance of females as light infantry soldiers.

A few countries permit women to serve in combat roles, but their long term performance in these positions has not been reported. The incidences of overuse injuries and attrition of 85 male and 235 female recruits in a light infantry brigade was followed in a three-year prospective study. Females were shorter (162 cm, CI 161-163 cm) than males (174 cm, CI 173-176), had more body fat (18.9 kg, CI 18.2-19.6 kg) than males (12.6 kg, 11.3-13.8 kg), had lower [Formula: see text]O2max (36.8 mL·min(-1) ·kg(-1), CI 35.8-37.78 mL·min(-1) ·kg(-1)) than males (50.48 mL·min(-1) ·kg(-1), CI 48.4 to 52.48 mL·min(-1) ·kg(-1)), had more stress fractures (21.0%, 95% CI 16.2-26.5%) than males (2.3%, CI 0.3-8.2%), and had more anterior knee pain (41.2%, CI 34.9-47.7%) than males (24.7%, CI 16.0-35.2%). Three-year attrition was 28% CI 22-34% for females and 37% CI 26-48% for males. The females in this study successfully served as light infantry soldiers. Their lower fitness and high incidence of overuse injuries might impede service as regular infantry soldiers.

Tibial stress changes in new combat recruits for special forces: patterns and timing at MR imaging.

PURPOSE: To characterize the incidence, location, grade, and patterns of magnetic resonance (MR) imaging findings in the tibia in asymptomatic recruits before and after 4-month basic training and to investigate whether MR imaging parameters correlated with pretraining activity levels or with future symptomatic injury. MATERIALS AND METHODS: This study was approved by three institutional review boards and was conducted in compliance with HIPAA requirements. Volunteers were included in the study after they signed informed consent forms. MR imaging of the tibia of 55 men entering the Israeli Special Forces was performed on recruitment day and after basic training. Ten recruits who did not perform vigorous self-training prior to and during service served as control subjects. MR imaging studies in all recruits were evaluated for presence, type, length, and location of bone stress changes in the tibia. Anthropometric measurements and activity history data were collected. Relationships between bone stress changes, physical activity, and clinical findings and between lesion size and progression were analyzed. RESULTS: Bone stress changes were seen in 35 of 55 recruits (in 26 recruits at time 0 and in nine recruits after basic training). Most bone stress changes consisted of endosteal marrow edema. Approximately 50% of bone stress changes occurred between the middle and distal thirds of the tibia. Lesion size at time 0 had significant correlation with progression. All endosteal findings smaller than 100 mm resolved or did not change, while most findings larger than 100 mm progressed. Of 10 control subjects, one had bone stress changes at time 0, and one had bone stress changes at 4 months. CONCLUSION: Most tibial bone stress changes occurred before basic training, were usually endosteal, occurred between the middle and distal thirds of the tibia, were smaller than 100 mm, and did not progress. These findings are presumed to represent normal bone remodeling.