Low Energy Availability (LEA) in Male Athletes: A Review of the Literature.

Purpose: Low energy availability (LEA) is a physiological state when there is inadequate energy to meet the demands placed on the body, often through physical activity, exercise, or sports. LEA can impact any athlete engaged in a sport with low energy intake or excessive energy expenditure. LEA is a precursor to the onset of The Male Athlete Triad (MAT) and Relative Energy Deficiency in Sport (RED-S). There is no defined low energy availability threshold specific to male athletes engaged in high-energy expenditure sports leading to MAT and RED-S. This literature review evaluates the literature on the relationship between LEA and signs or symptoms of MAT and RED-S to establish a low energy availability threshold specific to male athletes engaged in high-energy expenditure sports. Methods: The Pennsylvania Western University library electronic database was used for the literature search. Search terms included "male athletes", "low energy availability", "male athlete triad", "relative energy deficiency in sport", and "energy deficiency". Research studies included cross-sectional, experimental, systematic reviews, meta-analyses, case studies, and some narrative and literature reviews. Studies must have been peer-reviewed and published within five years of the literature search (12/2018- 12/2023). Results: A review of the literature shows that it is difficult to determine a LEA threshold due to present research gaps and inconsistent findings related to health and performance consequences. Based on the results of experimental studies, practitioners can expect an LEA threshold of 20-25kcal per kilogram (kg) of fat-free mass (FFM) per day in male athletes engaged in high energy-expenditure sports. Conclusions: Athletes engaged in sports that lead to inadequate energy intake or high energy expenditure are at risk for LEA, MAT, and RED-S. Experimental research on the LEA threshold in athletes engaged in physiologically demanding sports is the greatest research gap. Based on present findings, male athletes may have an LEA threshold of <30kcal/kg of FFM/day. Applications in Sport: Healthy nutritional practices are essential to sports performance. Interdisciplinary sports performance teams must collaborate with nutrition professionals to develop effective LEA prevention, screening, and intervention protocols. Keywords: energy intake, energy deficiency, energy expenditure of exercise, male athlete triad, relative energy deficiency in sport, sports nutrition [ABSTRACT FROM AUTHOR]