was thought to be inconsequential; however, recent data (Zhu and Haas, 1997) show that VO₂max and endurance in iron-depleted women without anemia are reduced and related to serum ferritin concentration (the index of iron storage) but not to hemoglobin.

Cognitive function and iron. Most studies on iron status and cognition to date have focused on infants and schoolchildren and have reported a negative impact of iron deficiency on behavior and development. It is unclear whether these deficits are reversible with iron treatment (IOM, 1993). Only a few studies have examined the impact of iron deficiency on cognitive function in adolescents and adults. Iron-deficient adolescent and young adult women who received iron treatment had better cognitive function than controls in several studies (Ballin et al., 1992; Bruner et al., 1996; Groner et al., 1986; Webb and Oski, 1973). However, one cross-sectional study of iron status in young adults reported no relationship between low iron stores and cognitive function, (Fordy and Benton, 1994). A study is in progress by Sandstead (1996) and coworkers to examine the role of iron supplementation and iron deficiency in the cognitive function of active-duty military women. More data in this area are needed, but the potential negative cognitive effects of iron deficiency and anemia, coupled with its negative physical effects, underscore the need to ensure that military women consume adequate amounts of iron to ensure readiness.

Impact of exercise on iron status. Most studies examining iron status and exercise have focused on highly trained athletes and have reported that iron losses are higher in endurance-trained athletes than in the reference groups (Weaver and Rajaram, 1992). A few studies report on the impact of exercise on the iron status of sedentary women as they first begin fitness exercise. Most of these studies found an initial decline in iron status (beyond that associated with hemodilution) among women at the start of the exercise program (Hegenauer et al., 1983; Kilbom, 1971; Lyle et al., 1992; Rajaram et al., 1995; Rowland et al., 1988). Data are conflicting on whether adaptation of iron status to fitness exercise occurs without increased iron intake via supplements or meat (Blum et al., 1986; Lyle et al., 1992; Rajaram et al., 1995). Athletes with iron deficiency severe enough to result in anemia improved their work performance with increased iron intake through food or supplements (Karamizrak et al., 1996), but the impact of increased iron intake on performance in nonanemic, iron-depleted athletes is less certain (Clarkson and Haymes, 1995; Karamizrak et al., 1996). Some preliminary evidence suggests that iron supplementation of nonanemic women can improve aerobic capacity (Personal communication, J. Haas, Cornell University, Ithaca, N.Y., 1997).

A prolonged inadequate intake of calcium may have negative effects on skeletal health. An adequate calcium intake is important for attaining peak bone mass during adolescence and early adulthood and maintaining skeletal mass after that time (Heaney, 1996).

Military women have the advantage of an active lifestyle. A recent review of 17 studies with mostly peri- and postmenopausal women concluded that a positive effect of physical activity

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)