Relative Energy Deficiency in Sport (RED-S)

Introduction

Relative Energy Deficiency in Sport (RED-S) (the updated model of the female athlete triad) was defined by the International Olympic Committee in 2014 as: ‘impaired physiological functioning caused by relative energy deficiency, and includes but is not limited to impairments of metabolic rate, menstrual function, bone health, immunity, protein synthesis, and cardiovascular health’ (1) This term has replaced the female athlete triad as we are now aware that this syndrome impacts both female and male individuals experiencing low energy availability.

Definitions

- Amenorrhea - An abnormal absence of menstruation (Oxford Dictionary, 2016) - Dysmenorrhea - Painful menstruation, typically involving abdominal cramps (Oxford Dictionary, 2016) - The Female Athlete Triad – The interrelationship of menstrual cycle dysfunction, reduced energy availability and reduced bone mineral density (Nazem and Ackerman, 2012) - Hypomenorrhea – Abnormally light menstrual bleeding (Yaffe et al., 1978) - Menarche – ‘The occurrence of the first menstrual period in the female adolescent’ (Lacroix et al., 2020) - Menorrhagia – Heavy menstrual blood loss (National Institute for Health and Care Excellence, 2018) - Menstrual cycle - The process of ovulation and menstruation (Oxford Dictionary, 2016) - Menstruation - The process of discharging blood and other material from the lining of the uterus at intervals of about one lunar month from puberty to the menopause, except during pregnancy (Oxford Dictionary, 2016) - Oligomenorrhea - Menstrual cycle length of greater than 45 days (Ibáñez et al., 2000) - Osteopenia - A medical condition in which the protein and mineral content of bone is reduced, but less severely than in osteoporosis (Oxford Dictionary, 2016) - Relative Energy Deficiency in Sport (RED-S) - This is impaired physiological function including, but not limited to impairment of: metabolic rate; menstrual function; bone health; immunity; protein synthesis; and cardiovascular health, caused by energy deficiency (Mountjoy et al., 2014)