461 CONCLUSION: The low knowledge scores suggest that the coached athletes are at a higher risk of DWCB. Likewise, they are likely to be misinformed about the importance of correct energy intake. The common notion that experience as an athlete or taking a nutrition course makes one a qualified nutrition educator, must be questioned. 1916 Board #177 May 31 2:00 PM - 3:30 PM Macronutrient Intake and Resting Metabolic Rate in Middle and Long Distance Recreational Female Runners Joanne DiFrancisco-Donoghue 1 , Mina Divan 1 , Ashley DeLuca 1 , Courtney Baranek 1 , William G. Werner 2 , Hallie Zwibel 1 . 1 New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY. 2 New York Institute of Technology, Old Westbury, NY. (No relevant relationships reported) Energy deficit due to caloric restriction and increased expenditure has been shown to decrease resting metabolic rate (RMR). However, it is unclear how much of this deficit creates the reduced RMR. PURPOSE: To examine macronutrient intake on resting metabolic rate and body composition in recreational female middle distance runners compared with long distance female runners. METHODS: Twenty-one female runners were recruited; 12 middle distance (age 23.6±1.19) and 9 long distance (age 24.4±1.3), who completed a 3- day dietary food recall on non- consecutive days. Subjects were grouped by weekly mileage; middle distance averaged 9.5±6.1 miles weekly and long distance runners averaged 30.5±7.4 miles weekly. Subjects completed a morning fasting 15- minute indirect calorimetry resting metabolic rate (RMR) and a body composition assessment using dual-energy X-ray absorptiometry. Kilocalorie and macronutrient intake were assessed utilizing an online application. Subjects were also given the BSQ-16A self-report questionnaire of body shape preoccupation typical of eating disorders. RESULTS: There was a significant difference in body fat % between the middle distance and long distance runners (31±4.3 vs 25.1±3.73, p=0.004) and in lean body mass % (63.8±4.2 vs 71.2±3.8). There were no significant differences in body mass index (21.4±2.0 vs 23.6 ±3.3, p=0.11). RMR was approaching a significance difference between groups with the long distance runners having a lower RMR and the middle distance runners demonstrating a higher RMR (1242.4 kcal±190.4 vs 1462.8 kcal± 281.2, p=0.06). Energy intake was similar between both long distance runners and middle distance runners, with both groups only eating minimally above their RMR (284.5±120.7 kcal above RMR vs 121±281.2 kcal above RMR). Results from the BSQ-16A revealed neither group suffered from body shape concern. CONCLUSIONS: Both middle distance runners and long distance runners demonstrated caloric restriction. Despite having significantly more lean body mass, long distance recreational runners had a lower RMR. This may have been due to the greater energy deficit and increased energy expenditure found in the long distance runners. 1917 Board #178 May 31 2:00 PM - 3:30 PM Current Energy Availability Is Not Associated With The Menstrual Status Among Japanese Female Athletes Eri TAKAI, Rie ISHIZAWA, Mika GOSHOZONO, Machiko OTAKA, Suguru TORII, Motoko TAGUCHI. Waseda University, Tokorozawa, Saitama, Japan. (No relevant relationships reported) PURPOSE: Energy availability (EA) is defined as dietary total energy intake (TEI) minus exercise energy expenditure (EEE) normalized to fat-free mass (FFM). It is well known that chronic reduction in EA, below 30 kcal/kg FFM/day, is associated with impairments of a variety of body function such as menstrual disorder, endocrine dysfunction and decreased bone mineral density (BMD). Little is known regarding EA and the physiological parameters of Japanese female athletes classified according to menstrual status. Therefore, this study aimed to determine the current EA status, hormonal status and BMD in Japanese female athletes. METHODS: Eighteen female collegiate athletes were classified into two groups; the eumenorrheic group (EU, 22±1 years, n = 7) and the menstrual disorder group (MD, 20±1 years, n = 11). The ovulation status was checked before the experimental period using an ovulation test kit, and the date were collected during the early follicular phase in EU group. TEI was assessed using 7-days dietary records, EEE was measured via HR-VO 2 methods, and hormonal status was measured from a fasting blood sample. Body composition and BMD were measured by dual energy X-ray absorptiometry. The eating attitude test (EAT-26) was used to assess susceptibility to eating disorders. RESULTS: EA was not significantly different between EU and MD groups (32.2±9.6 kcal/kg FFM/day vs 32.6±8.1 kcal/kg FFM/day). Further, no significant differences were observed in terms of body composition, BMD, and EAT-26 score between the two groups. However, triiodothyronine (T 3 ; 84±14 ng/dL vs 114±21 ng/dL, p<0.01) and progesterone (P 4 ; 0.2±0.1 ng/mL vs 0.4±0.1 ng/mL, p<0.05) were significantly lower in MD group than those in EU group. CONCLUSIONS: The results of the present study suggested that the menstrual status is not associated with current EA, but may be related to chronic energy deficiency among Japanese female athletes. 1918 Board #179 May 31 2:00 PM - 3:30 PM Effect Of Low Energy Availability During Three Consecutive Days Of Endurance Training On Muscle Glycogen Contents And Serum Hepcidin Levels In Male Long Distance Runners. Aya Ishibashi 1 , Chihiro Kojima 2 , Akiko Kamei 1 , Kaito Iwayama 1 , Yoko Tanabe 1 , Goto Kazushige 2 , Hideyuki Takahashi 1 . 1 Japan Institute of Sports Sciences, Tokyo, Japan. 2 Ritsumeikan University, Shiga, Japan. (No relevant relationships reported) PURPOSE: Hepcidin is a crucial mediator of iron homeostasis and may be associated with iron deficiency in response to exercise training. Exercise-induced interleukin-6 (IL-6) elevation stimulates hepcidin synthesis after exercise. Low energy availability induced by insufficient dietary energy intake during strenuous endurance training period in athletes, and it may elicit depletion of muscle glycogen contents. Moreover, lowered muscle glycogen content augments exercise-induced IL-6 elevation probably leading to increase in hepcidin levels. We investigated that effect of low energy availability during three consecutive days of endurance training on muscle glycogen contents and hepcidin levels. METHODS: Seven male long distance runners participated in the present study (mean ± standard error, age: 19.8 ± 0.4 yrs ; height : 1.75 ± 0.02 m ; body mass: 61.4 ± 2.0 kg). The present study was a repeated-measures crossover design. All subjects completed two exercise trials consisting of low energy availability (LEA) trial or neutral energy availability (NEA) trial. Energy availability was manipulated to set as 20 kcal / kg FFM / day for LEA trial and 45 kcal / kg FFM / day for NEA trial, respectively. The subjects completed three consecutive days of endurance training (75 min of treadmill running at 70 % of VO 2max ) during days 1-3. Venous blood samples were collected in early morning on days1-4 and 3 h after exercise completion on day 3. Serum hepcidin, ferritin, iron, myoglobin and plasma IL-6 levels were evaluated. Muscle glycogen contents were evaluated in early morning on days 1-4 by 13 C-MRS. RESULTS: Average energy intake was 2,081 ± 61 kcal / day in LEA trial and 3,967 ± 90 kcal / day in NEA trial (p < 0.001). Muscle glycogen content were decreased in LEA trial during days 2-4 (p < 0.05, vs. day1) whereas no significant change was observed in NEA trial. Area under the curve of serum hepcidin levels during days 1-4 was significantly higher in LEA trial (40.2 ± 11.8 ng/mL in LEA trial) than in the NEA trial (17.0 ± 7.0 ng/mL, p = 0.04). CONCLUSIONS: Three consecutive days of endurance training under LEA decreased muscle glycogen content and increased serum hepcidin levels in male long distance runners. 1919 Board #180 May 31 2:00 PM - 3:30 PM Development Of A Validated Energy Expenditure Prediction Equation In Asian Adults Xi Jin, Paul Dinneen Loprinzi, Martha Ann Bass, Ling Xin, Teresa Carr Carithers, Mark Loftin, FACSM. The University of Mississippi, University, MS. (No relevant relationships reported) Knowledge of energy expenditure (EE) is an important factor for weight management and helps fitness professionals more appropriately design exercise programs for obesity reduction in the obesity prevalence of Asian. PURPOSE: The aim of this study was to develop a regression equation to predict EE during walking or running corrected for one mile in normal weight and overweight Asian adults and to cross-validate the equation. Copyright © 2018 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.