The Female Athlete Triad: A Metabolic Phenomenon

Abstract

Loucks, A. B. (2014). The Female Athlete Triad: A Metabolic Phenomenon. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 12 (1), 1-23. The Female Athlete Triad (Triad) is a syndrome in which low energy availability triggers a broad range of endocrine mechanisms that conserve energy expenditure, and thereby impairs reproductive and skeletal health. Energy availability is the amount of dietary energy remaining after exercise training for all other physiological functions each day. The specific kind of reproductive dysfunctions caused by low energy availability are functional hypothalamic menstrual disorders. To ensure that affected athletes receive appropriate care, endocrine tests are required to diagnose these disorders by the exclusion of other types of menstrual disorders unrelated to the Triad. In addition, low energy availability impairs skeletal health by uncoupling bone turnover, in which the rate of bone resorption increases while the rate of bone formation declines. The result is a progressive loss or failure to accrue bone mass, which increases the risks of stress fractures and osteoporosis. Low energy availability originates in one or more of three sources: restrictive eating disorders, especially anorexia nervosa; intentional efforts to lose body weight or body fat to improve athletic performance or appearance; and the inadvertent suppression of appetite by exercise and diets containing a high percentage of carbohydrates. It is necessary to know the origin of low energy availability in a particular athlete in order to intervene effectively with her. The key behavior modification for preventing and treating the Triad is to increase energy availability, either by increasing dietary energy intake, reducing exercise energy expenditure, or both. Guidelines for doing so are provided. , 12 (1), 1-23. La tríada de la atleta (tríada) es un síndrome en el cual la baja disponibilidad de energía dispara una amplia gama de mecanismos endocrinos para disminuir el gasto energético, lo cual perjudica la salud reproductiva y esquelética. La disponibilidad energética es la cantidad de energía de la dieta que queda cada día, después del entrenamiento o el ejercicio, para todas las demás funciones fisiológicas. El tipo específico de mal funcionamiento reproductivo provocado por la baja disponibilidad energética son los trastornos menstruales hipotalámicos. Para asegurarse de que las atletas afectadas reciban la atención apropiada es necesario realizar pruebas endocrinas que sirven para diagnosticar los trastornos mencionados mediante la exclusión de otros trastornos menstruales no asociados con la tríada. La baja disponibilidad energética perjudica la salud esquelética debido al desacoplamiento del recambio óseo, en el cual la tasa de resorción aumenta mientras la tasa de formación de hueso desciende. El resultado es una pérdida progresiva de hueso o la incapacidad de acumular masa ósea, lo cual aumenta el riesgo de fracturas por estrés y de osteoporosis. La baja disponibilidad energética tien...

Low energy availability: history, definition and evidence of its endocrine, metabolic and physiological effects in prospective studies in females and males

“…In the third and most current definition, it is recognised that the value of gross exercise energy expenditure used in the previous definitions includes contribution of resting metabolic rate and non-exercise activity that should be subtracted to provide a net value of exercise energy expenditure (Loucks et al 1998 ). Further details of these definitions can be found elsewhere (Loucks 2014 , 2020 ).…”

“…Energy availability and adaptive thermogenesis As energy availability only accounts for intake and EEE and is therefore defined as an input into all physiological systems (Loucks 2004 , 2007a , 2007b , 2013 , 2014 ; Loucks et al 2011 ), its numerical value is by definition independent of all the other (dynamic) components of energy expenditure outside of exercise, and therefore unaffected by adaptive thermogenesis/energy conservation. This concept implies that optimal physiological function relies on an ‘adequate’ amount of energy availability and allows us to quantify the adequacy of energy available for metabolic processes independent of metabolic adaptation and body weight changes.…”