A Workshop Summary, Agenda, Participants, and Abstracts

Workshop Summary

Introduction

At the request of the sponsor, the Committee on Body Composition, Nutrition, and Health of Military Women (BCNH committee) held a workshop in Irvine, California, on September 9–10, 1996, entitled "Assessing Readiness in Military Women: The Relationship to Nutrition." The purpose of the workshop was to gather information from military personnel and civilian researchers on issues related to body composition, fitness, nutrition, and pregnancy as they pertained to active-duty servicewomen and to identify areas where further research is needed. This is a brief summary of the data presented and issues discussed. Included are references supplied by the guest speakers.



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--> A Workshop Summary, Agenda, Participants, and Abstracts Workshop Summary Introduction At the request of the sponsor, the Committee on Body Composition, Nutrition, and Health of Military Women (BCNH committee) held a workshop in Irvine, California, on September 9–10, 1996, entitled "Assessing Readiness in Military Women: The Relationship to Nutrition." The purpose of the workshop was to gather information from military personnel and civilian researchers on issues related to body composition, fitness, nutrition, and pregnancy as they pertained to active-duty servicewomen and to identify areas where further research is needed. This is a brief summary of the data presented and issues discussed. Included are references supplied by the guest speakers.

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--> Demographics Over 191,000 women serve on active duty in the U.S. Armed Forces (Verdugo, 1996), with another 140,000 women serving in the reserves (Herrold, 1996).1 Women constitute 13, 14, and 17 percent of the personnel serving on active duty in the Navy, Army, and Air Force, respectively, but only 5 percent of those serving on active duty in the Marine Corps. In FY1995, women comprised 19, 20, and 24 percent of those enlisting in the Army, Navy, and Air Force, respectively, and 6 percent of those enlisting in the Marine Corps (Verdugo, 1996). Women are better represented among new enlistees than among active-duty forces for two reasons: the percentage of female enlistees has been increasing over the past several years, and women have a higher rate of attrition from the military than men. The majority of women on active duty are enlisted personnel (84%), as are the majority of men (85%) (Bray, 1996). In each branch, the percentage of total enlisted personnel who are women is nearly identical to the percentage of total officers who are women. The military population is a young one. An estimated 50 percent of active-duty women are between the ages of 17 and 25, and only 6 percent are over the age of 40. The ethnic distribution among active-duty women differs from branch to branch and between enlisted personnel and officers. Overall, 40 percent of active-duty women classify themselves as minorities (African American, Hispanic, Asian American-Pacific Islander, Native American, and other). Minority group members comprise 53 percent of Army women (with the number of African American enlisted women exceeding the number of Caucasian enlisted women), 42 percent of Navy and Marine Corps enlisted women, and approximately 32 percent of Air Force enlisted women. (The percentage of minority women among officers is lower than that among enlisted women.) With the lifting of the combat exclusion laws in 1993, most positions in the military are now open to women, and occupational profiles of women have begun to change (Herrold, 1996). Although the majority of women still occupy support, administrative, and health care roles, more and more military women are accepting assignments to physically demanding jobs. According to data presented by Naomi Verdugo (1996), 50 percent of military women have completed some college, 50 percent are married, and 50 percent are parents. The military is concerned about maintaining the health and fitness of active-duty women (Bray, 1996; Verdugo, 1996). They are given free medical and dental care with an emphasis on preventive medicine and regular health checkups. In a survey of the four military services, 95 percent of active-duty women reported having had a Pap test in the last 3 years, and 82 percent reported that they received prenatal care in the first trimester of their last pregnancy (Bray, 1996). However, a substantial proportion of military women make lifestyle choices that put their health at risk. For example, an estimated 30 percent of active-duty women smoke, 70 percent use alcohol regularly, 40 percent do not exercise at least three times a week for 20 minutes or more, 40 percent do not eat two full meals a day at least 5 days a week, and 40 percent do not sleep more than 6 consecutive hours at least 5 days a week (Bray, 1996). 1   Data presented at this workshop are drawn from a variety of military surveys. A list of these surveys is presented in Table A-1.

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--> To maintain fitness and as part of their job, military women are expected to exercise and are screened at least annually for weight and fitness; however, anecdotal reports suggest that compliance with this expectation varies widely (see Table A-1; Bray, 1996; Friedman, 1996; Graham, 1996; Hernandez, 1996; Herrold, 1996; Picariello, 1996). An estimated 25 to 50 percent of women report that they currently exceed the military weight standard or have difficulty meeting the weight standard, while 5 to 15 percent report a height and weight that converts to a body mass index (BMI, weight in kilograms divided by the square of the height in meters) greater than 27 (Baker-Fulco, 1996; Bray, 1996; Hourani, 1996; Verdugo, 1996). It is not surprising then that a variety of studies of Army and Navy women have shown that from 42 to 79 percent are TABLE A-1 Surveys of U.S. Military Active-Duty Women Quoted by Speakers at the Workshop Speaker Survey Cited Sample Drake Eating Disorders Inventory U.S. Naval Academy cadets Baker-Fulco Total Army Injury and Health Outcomes Database Army active-duty personnel Baker-Fulco, King Eating Attitudes Feelings and Behavior Study Selected Army personnel Baker-Fulco, King Army Food and Nutrition Survey Selected Army personnel Baker-Fulco; King Brief study-unique questionnaires Selected Army personnel, U.S. Military Academy cadets Bray Survey of Health-Related Behaviors among Military Personnel Department of Defense active-duty personnel Jones Health Risk Appraisal Army active-duty personnel Hourani Nutrition Knowledge of Active-Duty Navy Personnel Navy active-duty personnel Hourani Longitudinal Analysis of Lifestyle, Health, and Readiness Navy active-duty personnel Hourani, Graham Perceptions of Wellness and Readiness Assessment Navy active-duty personnel Sbrocco Health Survey of the Air Force Air Force active-duty personnel Verdugo Sample Survey of Military Personnel Army active-duty personnel

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--> trying to lose weight at any given time (Baker-Fulco, 1996; Drake, 1996; Hourani, 1996; King, 1996; Sbrocco; 1996). Finally, an estimated 9 percent of active-duty women are pregnant at any given time. Available data suggest that pregnancy rates among active-duty women are lower than those of their age-matched civilian peers and that rates drop by more than 50 percent during troop deployment (Bray, 1996; Verdugo, 1996). Readiness from a Command Perspective CDR Susan B. Herrold, NC, USN (1996), presented to the BCNH committee an introduction to the components of military readiness. She stated that the primary mission of the military is to be warfighters, which leads to their operational primacy. According to Herrold, several factors have changed in military operations in recent years. These include the "operational tempo," or the rapidity of redeployment following completion of a mission, and the downsizing of the active-duty force, which has resulted in a decrease in the number of active-duty personnel. Both of these factors dictate that each individual soldier becomes much more important to the mission and has increased demands on her ability to perform. Overall readiness for a mission includes maximizing performance, minimizing unplanned losses, and adapting to changing environments; soldiers must be dependable, trained, healthy, physically fit, and well equipped. Among the day-to-day readiness issues, Herrold included health, fitness (both strength and flexibility), ability to withstand harsh environments (noise and extreme temperatures), and deployability at full-duty status (lack of injury or other incapacitating condition). Operational readiness issues include the ability to withstand irregular sleep and eating schedules, fatigue, limited medical resources, potential exposure to unfamiliar diseases, lack of hygiene, and such psychological stressors as lack of private toilet facilities. For women, this often results in voluntary decreases in fluid intake, leading to dehydration and its consequences. Herrold cited pregnancy and body composition issues as the most significant medical issues facing Navy women at the present time. She recommended that, although the Navy has taken the position that pregnancy is compatible with a Navy career, commanders must take the lead in advising young recruits to plan pregnancies at career-appropriate times. Body Composition And Fitness Policy and Rationale According to LTC Karl E. Friedl, USA (1996), the origin of military body fat standards can be traced to a report on the physical fitness of the services (DoD, 1981), commissioned by President Carter who, along with several generals, expressed concern about the decrease in fitness and increase in obesity among peace-time military personnel. In the 1981 report, appearance of unfitness was regarded as an indication of actual lack of fitness. Following the report came Department of Defense (DoD) Directive 1308.1 (1981), "Physical Fitness and Weight Control Programs," which required all services to institute a physical fitness program and

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--> weight control regulations, fitness evaluations (physical fitness tests or PFTs), body fat standards for accession and retention, and an appearance standard. The directive, written by a group that included physiologists, mandated a weight control program that would use measurement of body fat as the final discriminator of fitness. In response, each of the services devised its own weight control regulations. The first tier could be a weight screen, but this would be followed, if necessary, by a circumferentially based body fat determination (based on equations) using the standard of hydrodensitometry, which was the best standard available at the time. The Marine Corps already had devised its own anthropometric equations, whose primary aim, according to Friedl, was appearance, since appearance was viewed as an indicator of fitness and performance. Long-term health consequences were apparently only a secondary consideration to the developers of the original DoD standards. The original DoD recommendation limited body fat to 20 percent of body weight for men and 30 percent for women (15% and 25%, respectively, plus a 5% margin of error) based on physiological measures of fit young men and women, but some individuals providing input to the standards ordered a decrease in the 30 percent body fat for women to 26 percent because they saw no reason for women to carry that much more fat than men. A 1995 update of the original directive (DoDD 1308.1, "Physical Fitness and Body Fat Programs") now states that the maximum allowable limit for men is 26 percent and for women 36 percent, although each service maintains its own standards. The current Army regulation (AR 600-9, 1986) contains allowances for age, with four age categories. In comparison, the Air Force regulation (AFPD 40-5, 1994) contains one age break at 30, while the Navy and Marine Corps regulations (OPNAVINST 6110.1D, 1990) are age neutral. The higher body fat allowance for Army personnel over age 40 (26 and 36%, for men and women, respectively) is at least health based, according to Friedl, since it corresponds to the BMI that is the surgeon general's threshold for increased cardiovascular risk. All services use gender-adjusted body fat standards. The Army weight control program uses a weight-for-height screen as its first tier, followed by circumferential measures for those who exceed their weight limit. Data were shown from a 1988 study of male soldiers (O'Connor et al., 1990), illustrating that approximately half of those found to be overweight were within the allowable fat limits, which kept them out of the weight control program but which would be recorded in their records nonetheless. The validity of the circumferential equations used by the military was discussed by Friedl (1996). Equations based on circumferential measurements replaced those based on the more commonly used skinfold measures because of the greater reliability of circumferential measures in field conditions. The men's equations differ slightly from one service to another, but all of them focus on a measure of abdominal circumference (since this is the primary site of male fat deposition), correcting for body size by measuring the circumference of the neck. Although these equations have been validated against underwater weighing (based on a tow-compartment model of body composition), the latter method, itself, may not be valid for several reasons. Many military subjects cannot swim, resulting in a skewed sample or incorrect determinations. Moreover, one of the assumptions made in interpreting the data is that there are no individual differences in bone mineral density (BMD), when in fact there are significant ethnic differences in BMD. Efforts are being made to identify a better criterion method, such as the use of dualenergy x-ray absorptiometry (DXA) (based on a three-compartment model) and a four-compartment model that incorporates DXA. Although the male equations compare well

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--> with DXA, according to Friedl, the female equations (which differ significantly among services) do not, particularly when used to measure longitudinal changes in body fat. In a study conducted by Westphal and coworkers (1995) of 150 women going through Army basic combat training (BCT), the use of a measure based on weight for height (BMI) surpassed the equations of all services in predicting body fat loss measured by DXA. The equations tended to underpredict fat loss, in some cases indicating fat gain. Thus, Friedl (1996) recommended that the military consider replacing the anthropometric equations with simple BMI measurements, particularly for assessment of body fat loss or change in women. He also recommended more research on the time course and magnitude of changes in postpartum body composition and on the possibility that a lower minimal limit of body weight be set for women, in response to evidence that lower-weight women are at a significantly greater risk for early attrition. LCDR René S. Hernandez, USN, MSC (1996), described the rationale for the Navy's body fat standard, which is based on the Metropolitan Life Insurance Company's tables of recommended weight for height (1983). The Navy standards originally limited men's body fat to 22 percent and women's to 33 percent. For reasons of appearance, an internal administrative decision subsequently reduced the upper limit for women to 30 percent body fat. Reversal of this decision is now under consideration. According to Hernandez, the decrease in the women's body fat limit is an indication that men continue to be judged by a standard that is compatible with health, while women are held to a standard that is appearance based. She added that in order to avoid using "appearance" as a retention standard, appearance is evaluated unofficially under the category of "military bearing." Body composition standards for accession and retention for each branch of the military can be found in Appendix B, Table B-1. DoD Directive 1308.1 (1981) also includes a recommendation for fitness standards, and each service has developed programs and methods of evaluation of fitness (see Chapter 3 and Appendix B, Table B-1). The relationship of fitness to body composition and performance is not emphasized. CDR Wayne Z. McBride, MC, USN (1996), provided a brief presentation on the efforts of a DoD committee to equalize body composition standards for accession across all branches of the military services and to "age neutralize" these standards. McBride also presented the possibility that the body composition standard should be based on BMI rather than on heights and weights or body fat. The DoD effort to equalize standards is based on three perceived problems with current accession standards: first, height and weight accession standards currently allow both male and female recruits to exceed the service-specific body fat percentage limits for retention; second, a significant disparity exists in accession standards among the four branches. Finally, the difference between the maximum permissible accession weight for men and their maximum retention weight is greater than the comparable difference for women; thus, bias exists, with men judged to be qualified for accession at weights further from their ideal weight than are those for women. An analysis of the NHANES III database (Kuczmarski et al., 1994) also revealed that a significantly higher percentage of females than males in the general population would be disqualified from enlistment based on weight. The rationale for this difference is that according to statistics, male recruits lose significantly more weight than do female recruits during basic training, and men retain a greater weight loss. Friedl (1996) raised the question of whether there

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--> are gender differences in weight loss physiology that should be considered. A number of other military speakers and attendees at the workshop offered an alternative explanation for the observations, namely that many, if not most, active-duty women work in sedentary jobs that do not promote time for fitness. The question was raised regarding why appearance standards exist in the military and whether personnel would not be better served by eliminating these standards in favor of more stringent (job-related) fitness and body composition standards. Several of the military speakers expressed opposition to the appearance standard on the grounds that it is unrelated to health, fitness, and even body composition (a woman can be thin but overfat). COL Jeanne Picariello, USA (1996), emphasized that increasing the intensity of fitness training would increase fitness and decrease the number of personnel in danger of exceeding the weight standard. Friedl (1996) cited data showing that women with the largest waist-hip ratio have the greatest upper body strength but that these women are also at higher risk for cardiovascular disease, which illustrates the point that peak performance standards may at times conflict with health and appearance standards. Others acknowledged, however, that the appearance standard will not be abolished because of the importance to the military of appearance as a deterrent (that is, "show of force"). The group was asked to help guide the committee to establish body composition standards that will best serve women's health and fitness. One request was to provide a medical or scientific rationale on which to base these standards. James A. Hodgdon (1996) explained that the Navy's body composition tables are based on the Metropolitan Life Insurance tables (1983) so there is at least some health basis. Friedl (1996) suggested the need for multiple standards with built-in risk thresholds. Others mentioned the need to address the use of smoking as a weight control measure by some military personnel. The most salient point from this discussion was that the relationships among appearance, health, body composition, and fitness are not clear. The interaction between the latter two was the topic of the next session. Estimations of Percentage of Soldiers In and Out of Compliance Verdugo (1996) reported on the results of a spring 1995 Army self-report Sample Survey of Military Personnel of female soldiers. While the demographic data are summarized above in the introduction, survey data related to body composition and the difficulty women have meeting weight standards are reviewed here. These data are stratified according to ethnic group and military rank; data by military rank are presented in Table A-2. These self-reported data show clearly that female soldiers experience more difficulty meeting the weight standards than do male soldiers and that the higher ranked officers and enlisted women experience the greatest difficulty. As age increased, the difficulty for both men and women increased, but a greater percentage of female soldiers self-reported difficulty in meeting weight standards than did older male soldiers (Table A-2). Likewise, female soldiers were more likely to experience difficulty meeting the Army PFT (Table A-3).

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--> TABLE A-2 Percentage of U.S. Army Personnel Surveyed Who Self-Reported Difficulty Meeting Weight Standards   Rank of Officers Rank of Enlisted Personnel   01–03 04–06 E2–E4 E5–E6 E7–E9 Male 14 17 15 17 16 Female 20 28 23 26 28   SOURCE: Sample Survey of Military Personnel (Verdugo, 1996). Laurel L. Hourani (1996) summarized self-reported body composition data from the 1990 Survey of Nutrition Knowledge of Active-Duty Navy Personnel, a mail-in survey with approximately 3,000 respondents, of which 400 were female (73% response rate). Although only 9 percent of the females surveyed exceeded the percentage body fat standard (that is, 30% fat for females), 47 percent of the sample perceived themselves as overweight, and 60 percent were attempting to lose weight. More non-Caucasians than Caucasians exceeded the body fat standard, yet there was no difference in the percentages who were trying to lose weight. According to the survey, among those trying to lose weight, Caucasians relied equally on reducing caloric intake and increasing energy expenditure, whereas non-Caucasians were more likely to diet than exercise to lose weight. The problem of short-term dieting to meet the accession standards was highlighted by Hourani, who also noted that these same individuals may have chronic difficulties in meeting the retention standards if they fail to lose weight prior to weigh-in, which results in a pattern of weight cycling. Current proposals by the Navy include: (1) increase the allowable fat for women to 33 percent, and (2) develop fair standards for women who fall outside of the height range of 58 to 71 inches. Because these heights form the limits to the Metropolitan Life Insurance table, some assumptions are made that may result in more stringent standards for individuals whose heights fall above or below those limits. Robert M. Bray (1996) discussed the self-report Survey of Health-Related Behaviors among Military Personnel, which is conducted periodically among a cross-section of approximately TABLE A-3 Percentage of U.S. Army Personnel Surveyed Who Self-Reported Difficulty Meeting the Army Physical Fitness Test Requirements   Rank of Officers Rank of Enlisted Personnel   01–03 04–06 E2–E4 E5–E6 E7–E9 Male 5 8 16 9 8 Female 10 16 17 11 14   SOURCE: Sample Survey of Military Personnel (Verdugo, 1996).

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--> 16,000 military personnel worldwide. In the 1995 survey among all age groups, men were twice as likely as women to report being overweight. Women were more likely to report poor health, however, less likely to engage in regular strenuous physical exercise and less likely to eat two or more meals per day. Perceptions of Wellness and Readiness Assessment Wendy F. Graham (1996) presented the results of the 1995 Perceptions of Wellness and Readiness Assessment (POWR '95), a self-reported questionnaire study of 25,000 Navy and Marine Corps personnel. The goal of the study was to provide baseline anthropometric and strength characteristics and blood pressure. The most significant finding of this study was that, according to self-report, 46 percent of Navy women exceed the 30 percent body fat standard. Graham (1996) also reported that the largest proportion of women of all ethnic groups exceeding the height and weight standards are in the age ranges of 18 to 24 and 45 to 54. African American women fail to meet the standards more frequently than do other ethnic groups. Graham (1996) proposed the use of three standards for retention in the Armed Services: (1) appearance, (2) performance, and (3) physical and mental health. As assessment tools, she proposed the use of: (1) a measurement of truncal fat for appearance by measurement of waist-to-hip circumference ratio, (2) the physical assessment test for performance, and (3) BMI for health. In her opinion, this recommendation would account for the available pool of recruits and provide an ethnically equitable standard. Variation In Body Composition Due To Ethnicity Or Gender Lisa M. Stolarczyk (1996) presented data on ethnic differences in body composition. She indicated that although the densities of body compartments are based on cadaver analysis and are assumed to be constant (Table A-4), the possibility of inter- and intra-individual variability exists and depends on physiological conditions such as age, gender, diet, physical activity, genetics, and the degree of hydration of fat-free mass (FFM). The major ethnic variation in body composition is due to differences in bone density, skeletal muscle mass, and bone mineral mass TABLE A-4 Assumed Densities of Body Compartments from Cadaver Analysis Body Compartment Density (g/cc) Fat 0.901 Lean 1.100 Water 1.000   SOURCE: Data are from McArdle et al., 1996.

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--> among ethnic groups. Stolarczyk suggested that the densities of FFM differ among ethnic groups, ranging from 1.111 g/cc in Asians to 1.097 g/cc in some Caucasians, depending primarily on hydration. According to Stolarczyk (1996), prediction of body composition with a two-compartment model (fat and FFM) will systematically underestimate the relative body fat of Native American, African American, Asian, and Hispanic women by 2 to 4 percent because of differences in FFM density. Since the fat-free body density of Caucasian women may be less than 1.100 g/cc, their percentage body fat will be overestimated systematically by about 1 to 2 percent using the two-compartment model. Therefore, race- or ethnicity-specific conversion formulas should be used when estimating relative body fat from total body density to predict percentage body fat more accurately. The use of a four-compartment model for estimating body composition would predict percentage body fat more accurately in all ethnic groups or in soldiers of mixed ethnicities according to Stolarczyk (1996) because this method accounts for differences in a major determinant of FFM density, namely bone. The method requires estimation of total body water using deuterium dilution and of BMD using DXA. This technique cannot easily be done in the field due to the limitations of these methods in the field. Relationships Between Body Composition and Physical Performance Hodgdon (1996) reported the results of a study of 62 male and 34 female Navy personnel (Beckett and Hodgdon, 1987; Hodgdon, 1992), in which the relationships between body composition and physical performance were investigated. The military-related physical performance tasks of lifting and carrying were studied and correlated with body composition data derived from a two-compartment model of fat and FFM (via hydrodensitometry). FFM, but not fat mass, was correlated positively with maximal box lifting capacity, strength measures, and box carrying. There were significant gender differences, with men performing better than women on all tasks (10% of women could not lift 100 lb). When data were corrected for FFM, differences between male and female performance disappeared. According to Hodgdon, these data suggest that FFM could be used as a screening tool for various occupations within the military. Although fat mass was associated positively with weight-bearing exercise (lifting and carrying), it was associated negatively with box carrying capacity and running performance. Hodgdon cautioned that any weight-bearing activity also has an endurance component after about 5 minutes of exercise and that even weight lifting had an endurance component after that time. Hodgdon also pointed out that this study was somewhat skewed in favor of the fit female, as those who could not generate 150 lb of upper body strength were restricted from participation. Hodgdon (1996) also described two additional studies comparing circumference-based percentage body fat assessment with hydrostatic weighing or DXA (Beckett and Hodgdon, 1987; Jette et al., 1990). These studies indicated that anthropometrically based classification of body fat in military women is not significantly better than BMI. According to Hodgdon, a gender-fair weight control standard could be limited to weight or BMI for women. He also noted that simple anthropometrics do not accurately assess changes in body composition.

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--> Relatively weak relationships exist between percentage body fat and aerobic capacity, and there is no relationship between maximal lift capacity or other strength measures and adiposity. Gender-appropriate body fat and/or body weight standards combined with an appropriate level of support to the individual (for example, physical training programs, dietary counseling, and well-equipped fitness facilities) should enhance physical readiness of all soldiers. Fitness Tests and Programs At the workshop, representatives from the Army, Navy, and Air Force described the fitness evaluations and programs used within each service. Descriptions of the current fitness test for each of the services can be found in Appendix B, Table B-1. Picariello (1996) described the Army program for which she is responsible in her role as commander of the U.S. Army Physical Fitness School at Fort Benning, Georgia. Each year, this school trains 2,000 to 3,000 trainers who then work with the troops to assist them in developing ongoing, personal, physical fitness programs. The goal of these programs is to establish regular, intense training schedules so that personnel are able to accomplish their increasingly physical, demanding jobs. The programs are designed to be relevant and interesting by engaging troops in a variety of job-related activities. Intensity and duration of work are increased gradually so that troops have the satisfaction of continual improvement. Picariello emphasized that, within the Army, the physical fitness program is considered part of duty time. The major drawbacks to its success are the failure at the command level to support the physical fitness program as part of the soldier's duty, and the reticence on the part of the young soldier ''raised in a sedentary lifestyle." She recommended a 5-d/wk program, emphasizing strength and endurance to ensure military fitness. Picariello (1996) also described a 1994 study, the Army Physical Fitness Update Survey (Tomasi et al., 1995), conducted jointly by the U.S. Army Fitness School, U.S. Army Research Institute of Environmental Medicine, and U.S. Army Research Institute for the purpose of updating fitness standards (which were based on a sample of young men). In the 1994 study, 2,588 personnel were studied and found to be more fit than those surveyed in 1988, with half of the career women surpassing the maximum standard for the 2-mi run (twice the ratio of the career males) and female sit-up performance falling within 3 percent of that of males. Based on these results, Picariello recommended that fitness standards be adjusted for both genders, with sit-up and running test standards becoming more gender neutral and the push-up standard becoming less gender neutral. At the same time, she recommended de-emphasizing the PFT as a training goal, examining job requirements, increasing the intensity and work relatedness of physical training, and dealing with the health issues of smoking and repeated crash dieting. In de-emphasizing PFT as a training goal, she hopes to reorient the attitude of commanders and enlisted personnel to consider fitness training as an integral part of duty training and to avoid extreme behaviors to simply meet the PFT goal. Hernandez (1996) described the Navy's approach to fitness, which focuses on ongoing physical fitness similar to that described by Picariello for the Army, although no formal Navy fitness trainer program exists as yet. As Hernandez described, the purpose of the Navy fitness program is to maintain the physical and mental stamina of sailors. Hernandez described the

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--> The Female Athlete Triad: Effects On The Skeleton Michelle P. Warren, M.D., Women's Center for Health and Social Issues and Reproductive Endocrinology, St. Luke's-Roosevelt Hospital Center, New York, NY 10019. Currently at Columbia-Presbyterian Medical Center, New York, NY 10032-3784 The female athlete triad, the triad of amenorrhea, osteopenia, and eating disorders, has been the source of much publicity in the athlete. The basis of comorbidity of these variables was made in the setting of studies on exercise-induced amenorrhea. The mechanism by which caloric restriction and abnormal eating may compromise bone mass is unclear. Exercise, particularly of a strenuous nature, can have a profound effect on reproductive function. This problem has been documented in women who participate in a variety of sports, including running, swimming, and ballet dancing. The clinical manifestations include delayed menarche, secondary amenorrhea, and irregular menses with prolonged cycles or shortened cycles because of inadequate luteal phases. The incidence of this problem varies widely among numerous reports but appears to be more common in athletic groups in which dieting to remain thin is necessary, particularly if thinness presents an athletic or artistic advantage. Reproduction dysfunction may range from minor changes in reproductive hormone production to long-term cessation of menstrual cycles and prolonged hypoestrogenism. Thus, recent work has shown that the amenorrhea, particularly with endurance training, is associated with a high incidence of eating disorders. This varies with the athletic discipline but is a definite underlying theme. Intervals of hypoestrogenism associated with abnormal eating patterns may lead to premature bone loss or lack of bone accretion. Athletes with low bone density are susceptible to stress fractures due to overuse of bone weakened by osteopenia. A high incidence of scoliosis (23%) and stress fractures (46%) in a group of female ballet dancers has been reported. Scoliosis was most prevalent in the dancers with delayed menarche and rose significantly with increasing menarcheal age (p < 0.05) as did stress fractures (p < 0.01). The prevalence of stress fractures among dancers and runners with menstrual irregularities were found not only to have higher incidence of stress fractures (45% compared with 29% in regular runners) but also to have more multiple fractures. Deficiency in the exercise-induced increase in bone mass in stressed bones of amenorrheic ballet dancers has also been identified. The lack of bone strengthening that usually occurs in this setting appears to lead to an increase in fracture rate, particularly in women with delayed menarche. The bone most stressed by activity (metatarsal) is the most severely deficient. Normal dancers studied had a higher metatarsal density than other groups, while the amenorrheic dancers had the lowest. The spine shows similar trends, although the strengthening process was not as marked as in the foot. Aberrant nutrition and nutritional patterns may affect the skeleton even before changes in bone density are noted; dancers with recent stress fractures had a higher prevalence of both nutritional aberrations and weight fluctuations when compared with dancers without fractures, although differences in bone density were not noted. Treatment with estrogen replacement therapy is commonly suggested to maintain bone mass and encourage further accretion in young athletes. In a group of 26 amenorrheics, randomized into treatment with estrogen-progestin

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--> replacement therapy (Premarin 0.625 mg, Provera 10 mg for 10 days) or placebo for 2 years, no differences were noted in treated vs. untreated groups. Thus, other factors besides hypoestrogenism appear to affect the (lowered) bone mass seen in young women and replacement doses of estrogen-progestin do not appear to change bone mineral density significantly over a 2-y period. The exercise-induced osteopenia is most likely affected by nutritional factors, which, in turn, probably have an effect on bone by multiple mechanisms. The Impact Of Physical Fitness And Gender-Integrated Training On Risks Of Stress Fractures And Other Injuries Among Women In Army Basic Training COL Bruce H. Jones, USA, M.D., M.P.H., M. Canham, M. Nee, L. Mahony, and M. Smutok, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Grounds, MD 21010 and U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760 Historically, the incidence of injuries among women during Army BCT has been twice as high as for men (Bensel and Kish, 1983; Jones, 1983; Jones et al., 1993a; Kowal, 1980). The reported incidence of stress fractures among women has been even higher, 2 to 10 times higher than for men. Knowledge of the higher rates of injury among women in BCT caused concern that the incidence of injury might be even higher when training for men and women was integrated into the same units in 1994. To determine the impact of integrated training on the incidence of injury among women, a study was conducted at Fort Leonard Wood, Missouri, in November and December 1995. Because it has been well established that lower levels of physical fitness are associated with higher risks of injury for both men and women (Jones et al., 1993a, b), physical fitness also was examined during this study. The population for the study included men (N = 470) and women (N = 284) in 6 BCT companies in the sixth, seventh, or eighth week of training. The medical records of every trainee on the unit training rosters were screened for illnesses and injuries. An injury was defined as a musculoskeletal complaint requiring medical attention. Scores on the initial entry physical training test also were obtained for each participant. Overall, Fort Leonard Wood recruits had slower average run times, higher average weights, and higher average BMIs as compared to recruits in a similar study conducted at Fort Jackson in 1988 (see Table A-9). As with earlier studies, women entering BCT at Fort Leonard Wood exhibited lower levels of physical fitness than men. Analysis of data from two companies in their seventh week of training showed that the incidence of injury among women was found to be 1.6 times higher than for men (57% vs. 36%, p= 0.001). The stress fracture incidence was 2.5 times higher among women (9% vs. 3.6%, p = 0.06). These incidences of injury were somewhat higher than past rates for both men and women (see Table A-10) and may correspond to the lower physical fitness levels seen among the Fort Leonard Wood recruits. Similar to past reports (Bell and Jones, 1993; Jones et al., 1992; Jones et al., 1993a), men and women exhibiting lower levels of physical fitness as measured by run time experienced higher rates of injury than their more fit peers. Male recruits with slower run times had

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--> TABLE A-9 Physical Fitness of Men and Women Starting Army Basic Combat Training: A Comparison of 1995 and 1988 Data Measurements Ft. LW, 1995 Men Mean (SD) Ft. Jackson, 1988 Men Mean (SD) Ft. LW, 1995 Women Mean (SD) Ft. Jackson, 1988 Women Mean (SD) 2-mi run time 17.3 (2.4) 16.4 (2.2) 22.5 (2.7) 20.3 (2.3) Height 175.5 (8.5) 175.2 (7.1) 161.5 (7.3) 162.0 (6.5) Weight 77.2 (12.3) 75.7 (12.2) 62.1 (7.6) 58.3 (6.5) BMI (wt/ht2) 25.1 (2.4) 24.6 (3.6) 23.0 (2.4) 22.2 (2.0)   SOURCE: Adapted from Canham et al. (1996) and Jones (1996). significantly higher incidences of both overall injury (see Table A-11) and stress fractures (see Table A-12). Female recruits with slower run times had significantly higher incidence of stress fractures (see Table A-13) but did not exhibit significantly higher incidence of overall injury as compared to their faster peers (risk ratio, slow vs. fast = 1.3, p = 0.8). Also, as with several past studies (Bell and Jones, 1993; Jones et al., 1992), the incidence of injury was found to be similar for men and women of the same aerobic fitness level (i.e., when fitness was controlled for by stratified analysis the incidence of injury was similar for both genders, risk ratio, women vs. men = 1.2, p = 0.64). We concluded that integrated training did not increase the risk of injury among women in this population and that low levels of physical fitness were an important risk factor for men and women. TABLE A-10 Incidence of Women and Men Injured During Basic Training Reported in Previous Studies from 1980 to 1995 Author Post Year Weeks in Training Women (%) Men (%) Relative Risk* — Ft. LW 1995 7 57 36 1.6 Reynolds Ft. Jackson 1993 8 67 — — Bell Ft. Jackson 1988 8 62 29 2.1 Jones Ft. Jackson 1984 7 50 28 1.8 Bensel Ft. Jackson 1983 8 42 23 1.8 Kowal Ft. Jackson 1980 8 54 26 2.1 * Relative risk, incidence in women/incidence in men. SOURCE: Adapted from Canham et al. (1996) and Jones (1996).

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--> TABLE A-11 Two-Mile Run Time and Incidence (%) of Injury Among Male Trainees at Fort Leonard Wood,* 1995 Quartile of run time (minutes) n Risk (%) of injury Q1 (1–15.72) 39 26 Q2 (15.73–17.33) 40 25 Q3 (17.34–19.05) 38 40 Q4 (19.06+) 38 50 NOTE: Risk ratio (slow vs. fast) = 1.8, p = 0.01, 95% CI = 1.1, 2.8; Chi-square for trend = 6.5, p = 0.01. * Companies in their seventh week of training SOURCE: Adapted from Canham et al. (1996) and Jones (1996). TABLE A-12 Two-Mile Run Time and Incidence (%) of Stress Fractures* Among Male Trainees at Fort Leonard Wood†, 1995 Run time half (minutes) n Risk (%) of stress fracture H1 (1–17.33) 79 1 H2 (17.34+) 76 10 NOTE: Risk ratio (slow vs. fast) = 7.3, p = 0.03, 95% CI = 0.9, 57.7. * Includes stress reactions and stress fractures. † Companies in their seventh week of training. SOURCE: Adapted from Canham et al. (1996) and Jones (1996). TABLE A-13 Two-Mile Run and Incidence (%) of Stress Fractures* Among Female Trainees at Fort Leonard Wood†, 1995 Run time half (minutes) n Risk (%) of stress fracture H1 (1–22.67) 48 10 H2 (22.68+) 47 26 NOTE: Risk ratio (slow vs. fast) = 2.5, p = 0.06, 95% CI = 0.9, 6.4. * Includes stress reactions and stress fractures. † Companies in their seventh week of training. SOURCE: Adapted from Canham et al. (1996) and Jones (1996).

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--> Bell, N., and B.H. Jones. 1993. Injury risk factors among male and female Army trainees [abstract]. 121st meeting of the American Public Health Association. Bensel, C.K., and R.N. Kish. 1983. Lower extremity disorders among men and women in Army basic training and effects of two types of boots. Technical Report No. TR-83/026. Natick, Mass.: U.S. Army Natick Research and Development Laboratories . Canham, M.L., M.A. McFerren, and B.H. Jones. 1996. The association of injury with physical fitness among men and women in gender integrated basic combat training units. Med. Surveill. Mon. Rep. 2(4):8–9. Jones, B.H. 1983. Overuse injuries of the lower extremities associated with marching, jogging, and running: A review. Mil. Med. 148:783–787. Jones, B.H. 1996. Injuries among women and men in gender integrated BCT units Fort Leonard Wood 1995. Med. Surveill. Mon. Rep. 2(2):2–3, 7–8. Jones, B.H., M.W. Bovee, and J.J. Knapik. 1992. Associations among body composition, physical fitness, and injury in men and women Army trainees. Pp. 141–172 in Body Composition and Physical Performance, Applications for the Military Services, B.M. Marriott and J. Grumstrup-Scott, eds. Committee on Military Nutrition Research, Food and Nutrition Board, Institute of Medicine. Washington, D.C.: National Academy Press. Jones, B.H., M.W. Bovee, J.M. Harris III, and D.N. Cowan. 1993a. Intrinsic risk factors for exercise-related injuries among male and female Army trainees. Am. J. Sports Med. 21:705–710. Jones, B.H. D.N. Cowan, J.P. Tomlinson, J.R. Robinson, D.W. Polly, and P.N. Frykman. 1993b. Epidemiology of injuries associated with physical training among young men in the Army. Med. Sci. Sports. Exerc. 25(2):197–203. Kowal, D. 1980. Nature and causes of injuries in women resulting from an endurance training program. Am. J. Sports. Med. 8(4):265–269. Clinical Impact Of U.S. Army Policies And Procedures On Pregnancy, The Postpartum Period, And Body Composition: Twenty Years Of Experience Paul N. Smith, COL MC USA (Ret), M.D., The Lakewood Clinic, Tacoma, WA 98499 Pregnant soldiers are issued an activity profile that is designed to "…protect the fetus while ensuring the productive utilization of the servicewoman." That goal seems to be achieved, although some studies have suggested that active-duty status is an independent risk factor for pregnancy (e.g., Magann and Nolan, 1991). Pregnancy outcomes are not improved over the general population in spite of defined limitation of work and ready access to health care. Pregnant soldiers are excused from the Army Body Composition Program standards and from physical fitness testing for the duration of the pregnancy. Postpartum soldiers are excused from those requirements for 6 months after delivery. Pregnant soldiers are detrimental to unit readiness through nondeployability, activity limitations, lost duty time, and unit morale effects. There was an explosion of promiscuity among female soldiers in Europe beginning late 1991 when VIIth Corps deployment to the Gulf was announced, since pregnancy meant nondeployability. As an indicator, sexually-transmitted-disease rates in female American soldiers in Würzburg, Germany during that time increased several hundred percent. Female soldiers constituted only 6 percent of the Americans in the Gulf but accounted for 18 percent of the sick-call workload. Sixty percent of field hospital admissions

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--> in the Gulf War were for pregnancy complications, and most evacuations of women were for pregnancy. The Army Body Composition Program provides for body fat determination for soldiers who exceed screening weight or whose appearance suggests excessive body fat. Soldiers who exceed body fat standards have favorable personnel actions suspended: nonpromotable, no command, no professional military schooling. The Army expends literally hundreds of thousands of manhours annually on the Army Body Composition Program. In my personal conversations during my career with more than 50 current and former commanders, ranging in rank from 2LT to MG, not one of those officers thinks that the Army Body Composition Program helps them field better warfighters. Changing demographics of the U.S. population suggest that current Army Body Composition Program standards may not fit the solders of Army 21 well. The correlation between body fat and fitness is weak; the absence of policies which censure soldiers for tobacco use or excessive alcohol use undermines the assertion that the Army Body Composition Program is health-motivated rather than purely cosmetic. The Army Body Composition Program should be discontinued, and the manhours currently consumed by the Army Body Composition Program should be diverted to battle drills and other activities which will enhance readiness. Research concerning body composition, nutrition, and physical training should focus on identifying valid performance criteria for selecting and training soldiers. References Magann, E.F., and T.E. Nolan. 1991. Pregnancy outcome in an active-duty population. Obstet. Gynecol. 78(part 1):391–393. The Impact Of Pregnancy Weight Restriction, Postpartum Exercise, And Weight Loss On Lactation Kathryn G. Dewey, Ph.D., and Megan A. McCrory, M.S., Department of Nutrition, University of California, Davis, CA 95616 Pregnancy Weight Restriction and Lactation Performance Observational studies performed in industrialized countries have not shown a direct association between pregnancy weight gain and lactational performance. However, since mothers who gain more weight tend to have higher birth weight infants and higher fat stores than mothers who gain less weight, there may be an indirect association of pregnancy weight gain with lactational performance by the following two mechanisms. First, there is a positive relationship between infant milk intake and birth weight, due to the fact that larger infants demand more milk than smaller infants. Second, milk fat concentration is positively associated with maternal fatness. On the other hand, the impact of maternal fatness on milk energy output is modified by infant self regulation, such that infants of mothers with high milk fat will demand a lower milk volume. The model put forth by Perez-Escamilla et al. (1995) illustrates the relationships among maternal fatness, birthweight, and the role of the infant in determining infant milk energy intake

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--> (Figure A-3). This model is consistent with the physiological regulation of lactation, which operates through endocrine and autocrine mechanisms governed by infant demand. Thus, within the range of weight gain normally observed during pregnancy, there is no evidence that pregnancy weight gain restriction will affect lactation performance. Lactation and Weight Loss The question of whether exercise poses any harm to maternal milk supply was first studied by Lovelady et al. (1990). There were no significant differences in lactation outcomes between lactating women who exercised aerobically for an average of 88 min/d and those who did not exercise. Because subjects in that study were self-selected, the same research group next undertook a randomized intervention trial (Dewey et al., 1994). Thirty-three exclusively breastfeeding women were assigned to either an aerobic exercise group (45 min/d, 5 d/wk) or a control group (no vigorous exercise > 1 d/wk) for 12 weeks. Although mothers in the exercise group increased their total daily energy expenditure by 400 kcal/d at the midpoint of the intervention compared to the control group (p < 0.05), there was little difference at the end of the intervention period because the exercising mothers cut back on other types of activities. There was no adverse impact of the exercise program on lactational performance. In addition, aerobic capacity significantly improved in the exercisers compared to controls p < 0.05). However, there was no difference in weight or body fat loss in the exercising group compared to the control group because the exercise group increased their energy intake. High intensity exercise has been shown to cause a transitory increase in breast milk lactic acid concentration (Wallace et al., 1992), but this is not harmful to the infant. Although some infants may find the more acidic taste less ''acceptable," this is not likely to interfere with milk intake in most cases. FIGURE A-3 Model illustrating the relationships among maternal fatness, birth weight, and the role of the infant in determining infant milk energy intake. SOURCE: Perez-Escamilla et al. (1995), used with permission (© American Journal of Clinical Nutrition, American Society for Clinical Nutrition).

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--> A gradual weight loss of about 0.8 kg/mo is normal during lactation. In fact, breastfeeding usually promotes weight loss (see Table A-14). In the 11 studies that have examined the impact of breastfeeding on postpartum weight loss, the results are mixed. But of the seven studies in which breastfeeding was clearly defined by more than simply yes/no or any/non (e.g., duration was known), six show that breastfeeding is related to greater maternal weight loss, or less maternal weight retention (defined as current minus prepregnancy weight). Studies in which skinfold thicknesses of postpartum mothers were measured demonstrate that there is a loss of fat associated with breastfeeding. There is no evidence that moderate weight loss (up to 2 kg/mo), in overweight women, has adverse effects on lactation. However, the effects of rapid weight loss are unknown. Lactation may be more vulnerable to the effects of weight loss in the first month postpartum, but there have been no studies on this question. Currently, the Institute of Medicine advises that lactating women who want to lose weight take in no less than 1,800 kcal/d, drink plenty of water, avoid liquid diets or weight loss medications, and continue to nurse on demand. Additional studies in this area are currently underway, which should provide more specific advice concerning weight loss among breastfeeding women. References Adair, L.S., and B.M. Popkin. 1992. Prolonged lactation contributes to depletion of maternal energy reserves in Filipino women. J. Nutr. 122(8):1643–1655. Boardley, D.J., R.G. Sargent, A.L. Coker, J.R. Hussey, and P.A. Sharpe. 1995. The relationship between diet, activity, and other factors, and postpartum weight change by race. Obstet. Gynecol. 86:834–838. Dewey, K.G., M.J. Heinig, and L.A. Nommsen. 1993. Maternal weight-loss patterns during prolonged lactation. Am. J. Clin. Nutr. 58:162–166. Dewey, K.G., C.A. Lovelady, L.A. Nommsen-Rivers, M.A. McCrory, and B. Lonnerdal. 1994. A randomized study of the effects of aerobic exercise by lactating women on breast-milk volume and composition. N. Engl. J. Med. 330:449–453. Janney, C.A., D. Zhang, and M.F. Sowers. 1997. Lactation and weight retention. Am. J. Clin. Nutr. 66(5):1116–1124. Keppel, K.G., and S.M. Taffel. 1993. Pregnancy-related weight gain and retention: Implications of the 1990 Institute of Medicine guidelines. Am. J. Public Health 83:1100–1103. Kramer, F.M., A.J. Stunkard, K.A. Marshall, S. McKinney, and J. Liebschutz. 1993. Breastfeeding reduces maternal lower-body fat. J. Am. Diet. Assoc. 93:429–433. Lovelady, C.A., B. Lonnerdal, and K.G. Dewey. 1990. Lactation performance of exercising women. Am. J. Clin. Nutr. 52:103–109. Öhlin, A., and S. Rössner. 1990. Maternal body weight development after pregnancy. Int. J. Obes. 14:159–173. Parker, J.D., and B. Abrams. 1993. Differences in postpartum weight retention between black and white mothers. Obstet. Gynecol. 81:768–774. Perez-Escamilla, R., R.J. Cohen, K.H. Brown, L.L. Rivera, J. Canahuati, and K.G. Dewey. 1995. Maternal anthropometric status and lactation performance in a low-income Honduran population: Evidence for the role of infants. Am. J. Clin. Nutr. 61:528–534. Potter, S., S. Hannum, B. McFarlin, D. Essex-Sorlie, E. Campbell, and S. Trupin. 1991. Does infant feeding method influence maternal postpartum weight loss? J. Am. Diet. Assoc. 91:441–446.

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--> TABLE A-14 Lactation and Postpartum Weight Loss Reference Location N Design Def. BF Outcome Results Comments Öhlin and Rössner, 1990 Sweden 1,423 Prosp. Score Weight loss Significant 2.5–6 months only Potter et al., 1991 United States 411 Retro. BF > 6 weeks Estimated weight loss Not significant or positive   Schauberger et al., 1992 United States 795 Prosp. Yes/no Weight loss Not significant   Adair and Popkin, 1992 Philippines 3,051 Prosp. Duration and intensity Weight loss Significant Also skinfold Dewey et al., 1993 United States 85 Prosp. (matched cohorts) BF > 12 months Weight loss Significant Also skinfold, excluded dieters Parker and Abrams, 1993 United States 2,119 Retro. Duration and intensity Excess weight retention Not significant   Keppel and Taffel, 1993 United States 2,944 Retro. BF > 4 months Weight retention Significant?   Kramer et al., 1993 United States 24 Prosp. BF > 6 months Weight loss Significant Also skinfold Boardley et al., 1995 United States 345 Retro. Any BF Weight retention Not significant Low %FBF Scholl et al., 1995 United States 274 Prosp. Any BF Weight retention Not significant Low %BF Janney et al., 1997 United States 110 Prosp. Duration and intensity Weight retention Significant  

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--> Schauberger, C.W., B.L. Rooney, and L.M. Brimer. 1992. Factors that influence weight loss in the puerperium. Obstet. Gynecol. 79:424–429. Scholl, T.O., M.L. Hediger, J.I. Schall, I.G. Ances, and W.K. Smith. 1995. Gestational weight gain, pregnancy outcome, and postpartum weight retention. Obstet. Gynecol. 86:423–427. Wallace, J.P., G. Inbar, and K. Ernsthaüsen. 1992. Infant acceptance of postexercise breastmilk. Pediatrics 89:1245–1247. Pregnancy Among Navy Women CDR Michael John Hughey, MC, USNR, M.D., Northwestern University Medical School, Wilmette, IL 60091 Pregnancy is not an illness, but is a time of physiologic changes which: (1) diminish some physical skills, (2) increase vulnerability to common hazards, (3) may lead to pregnancy-specific illnesses, and (4) leave the fetus vulnerable to common environmental hazards. Policies regarding the assignment and utilization of pregnant servicewomen in the Navy are based on the known pregnancy physiologic changes, perinatal risks, and known or suspected environmental hazards. Such policies include the "20-week rule," the "6-hour rule," and the "Commanding Officer's Prerogative." Overseas assignments often are restricted. Physical training is restricted during pregnancy and for 6 months following delivery.

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