In this concluding chapter, we would like to reflect on what has been written and assembled in this clinical guide and future research directions. Since passage of the Title IX legislation in 1972, more and more young women engage in physical activity and competitive sports. This opportunity and trend for girls and women to become more athletic has been positive overall, yet has also been accompanied by negative health outcomes for young women. While we have made advances in this area, there remain many gaps in knowledge that drive a future research agenda. We hope to summarize and reflect on important topics for future research.

Recently, the International Olympic Committee (IOC) convened an expert panel to update their consensus statement on the Female Athlete Triad [1]. The IOC working group introduced a broader, more comprehensive term as part of their 2014 statement and endorsed the new term, “Relative Energy Deficiency in Sport” (RED-S) over the previous terminology, “Female Athlete Triad.” They recognized the complexity involved in arriving at the most appropriate terminology and fact that male athletes are also affected. RED-S refers to impaired physiological functioning, which may include alterations in metabolic rate, menstrual function, hormonal changes, bone health, immunity, protein synthesis, and cardiovascular health caused by a relative energy deficiency. The primary aim of the IOC is to protect the health of athletes. Thus, the expansion of this term is deemed to align with the Committee’s primary mission. Research will be needed to define the prevalence/incidences of RED-S compared with the traditional components of the more well-known term, Female Athlete Triad. It will also be important to consider both distinctions and similarities between the two. As has occurred for reports pertaining to the Triad, significant variability can result among studies as differing definitions may be used (e.g., menstrual disorders, disordered eating, osteoporosis). Thus it can be difficult to draw conclusions in this area as different investigative groups may consider varying outcomes. Estimating the prevalence using either terminology with reasonable validity and precision becomes extraordinarily difficult because of the varying ways in which the Triad and its components have been conceptualized and operationalized over many years. This classification will remain a challenge for clinicians and researchers in the years to come.