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.

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.

Front Matter (R1-R16)

Executive Summary (1-24)

1 Introduction (25-32)

2 Body Composition (33-60)

3 Physical Fitness Policies and Programs (61-86)

4 Weight Management (87-108)

5 Nutritional Concerns of Military Women (109-126)

6 Pregnancy and Lactation and Postpartum Return-To-Duty Fitness (127-156)

7 Conclusions and Recommendations (157-170)

Appendixes (171-172)

A Workshop Summary, Agenda, Participants, and Abstracts (173-252)

B Practices and Policies Tables (253-262)

C Military Occupational Specialty Classification Tables (263-280)

D Search Strategy for Literature Review (281-284)

E Civilian Inquiry Letter and Table of Responses (285-290)

F Abbreviations (291-294)

G Bibliography (295-334)

H Biographical Sketches (335-338)

Index (339-352)