Adolescent Endurance Runners Exhibit Suboptimal Energy Availability and Intakes of Key Nutrients

Abstract

Backgroud: Despite the evidence of an elevated prevalence of low bone mass in adolescent endurance runners, reports on dietary intake in this population is limited.

Objectives: This study aimed to evaluate energy availability (EA) and dietary intake among 72 (n = 60 female, n = 12 male) high school cross-country runners.

Methods: The sample consisted of a combined dataset of two cohorts. In both cohorts, the Block Food Frequency Questionnaire (FFQ; 2005 & 2014 versions) assessed dietary intake. Fat free mass was assessed using dual-energy x-ray absorptiometry or bioelectrical impedance analysis.

Results: Mean EA was less than recommended (45 kcal/kgFFM/day) among male (35.8 ± 14.4 kcal/kg FFM/day) and female endurance runners (29.6 ± 17.4 kcal/kgFFM/day), with 30.0% of males and 60.0% of females meeting criteria for low EA (<30 kcal/kgFFM/day). Calorie intake for male (2,614.2 ± 861.8 kcal/day) and female (1,879.5 ± 723.6 kcal/day) endurance runners fell below the estimated energy requirement for “active” boys (>3,100 kcal/day) and girls (>2,300 kcal/day). Female endurance runners’ relative carbohydrate intake (4.9 ± 2.1 g/kg/day) also fell below recommended levels (6-10 g/kg/day). Male and female endurance runners exhibited below-recommended intakes of calcium, vitamin D, potassium, fruit, vegetables, grains, and dairy. Compared to male endurance runners, female endurance runners demonstrated lower relative intakes of energy (kcal/kg/day), protein (g/kg/day), fat (g/kg/day), fiber, vegetables, total protein, and oils.

Conclusion: This study provides evidence of the nutritional risk of adolescent endurance runners and underscores the importance of nutritional support efforts in this population.

Keywords:

• Female Athlete Triad
• bone mineral density
• food frequency questionnaire
• dietary assessment
• carbohydrate

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The study was funded by grants from the University of California Davis, Center for Health and Nutrition Research and the American College of Sports Medicine Foundation.