Examining Energy Availability Using Self-reported And Objective Data

Severe health complications (e.g., osteoporosis, hypothalamic amenorrhea (females) or hypogonadism (males), decreased energy metabolism, etc.) may occur due to low energy availability (LEA). Methods to assess total daily energy expenditure (TDEE) and exercise energy expenditure (EEE), include but are not limited to use of self-reported logs, scientific equations, accelerometers, and heart rate (HR) monitors. PURPOSE: To examine energy availability (EA) in endurance runners using a secondary analysis comparing two methods used to calculate EEE (self-reported exercise logs and HR monitors). METHODS: Data from a larger cross-sectional study design in a free-living environment was used. Endurance runners (n = 17, females: n = 10, height = 162.2 ± 5.6 cm, weight = 58.0 ± 7.9 kg; males: n = 7 height = 180.4 ± 6.6 cm, weight = 68.1 ± 5.5 kg) completed a basic demographic survey, anthropometric measurements (i.e., height, weight, body composition) and tracked their planned/intentional exercise and dietary intake using a self-reported food log. Participants wore a HR monitor throughout the day to capture TDEE and track EEE for 7 consecutive days. Descriptive statistics were used for all demographic variables. Crosstabulations and Chi-square analysis determined the proportion of participants “at risk” for LEA and sex, and independent t-tests compared differences in mean EEE using self-reported and objective data. RESULTS: Average EA was below the recommended 30 kcal/kg of FFM threshold, with 58.8% (n = 10/17) of endurance runners presenting with LEA, and no significant differences across sex (χ2 = .781, p = .377). Specifically, 50% (n = 5/10) of females displayed risk for LEA compared to males at 71.4% (n = 5/7). Paired sample T-tests revealed a significant difference (p < .001) between watch EEE (554.7 ± 238.6) and self-reported EEE (654.3 ± 289.1). Bland-Altman analysis depicted differences between data from watch EEE and self-reported EEE. CONCLUSIONS: High prevalence of LEA across endurance trained runners exists and there is a need for educational interventions on the negative outcomes. Objective data is necessary to make accurate estimates of EA to be able to detect early onset of signs and symptoms of the Female and Male Athlete Triad.