Relative Energy Deficiency Research Articles

Female Athlete Triad and Male Athlete Triad Syndrome Induced by Low Energy Availability: An Animal Model

Energy availability (EA) is defined the difference in energy intake and exercise energy expenditure. Reduction of EA (i.e. Low energy availability, LEA) often causes abnormalities of reproduction system and drastic bone loss in some female athletes, the phenomenon is called as female athlete triad. More than ever before, it is considered a serious problem, the reason of these are (1) the syndrome occurred in female athletes but also male athletes, (2) LEA is leads to dysfunction of various organs other than reproductive system (Relative energy deficiency in sport, RED-S). On the other hand, we have focused on this syndrome and have proposed novel insights into the physiological effects of LEA on bone and solutions through nutritional treatment by recreating it in animal models. In this review, we will summarize the epidemiological and physiological perspectives of these diseases from historical background to recent findings, and introduce the usefulness of using animal models to explore mechanisms and treatments.

Risk of Low Energy Availability, Disordered Eating, Exercise Addiction, and Food Intolerances in Female Endurance Athletes.

Relative energy deficiency in sport (RED-S) is a complex syndrome describing health and performance consequences of low energy availability (LEA) and is common among female endurance athletes. Various underlying causes of LEA have been reported, including disordered eating behavior (DE), but studies investigating the association with exercise addiction and food intolerances are lacking. Therefore, the aim of this cross-sectional study was to investigate the association between DE, exercise addiction and food intolerances in athletes at risk of LEA compared to those with low risk. Female endurance athletes, 18–35 years, training ≥5 times/week were recruited in Norway, Sweden, Ireland, and Germany. Participants completed an online-survey comprising the LEA in Females Questionnaire (LEAF-Q), Exercise Addiction Inventory (EAI), Eating Disorder Examination Questionnaire (EDE-Q), and questions regarding food intolerances. Of the 202 participants who met the inclusion criteria and completed the online survey, 65% were at risk of LEA, 23% were at risk of exercise addiction, and 21% had DE. Athletes at risk of LEA had higher EDE-Q and EAI scores compared to athletes with low risk. EAI score remained higher in athletes with risk of LEA after excluding athletes with DE. Athletes at risk of LEA did not report more food intolerances (17 vs. 10%, P = 0.198), but were more frequently reported by athletes with DE (28 vs. 11%, P = 0.004). In conclusion, these athletes had a high risk of LEA, exercise addiction, and DE. Exercise addiction should be considered as an additional risk factor in the prevention, early detection, and targeted treatment of RED-S among female endurance athletes.

Etiology and management of amenorrhea in adolescent and young adult women

In this article, we will review the etiology and management of amenorrhea in adolescent and young adult women, beginning with the diagnostic work-up and followed by etiologies organized by system. Most cases of amenorrhea are caused by dysfunction of the hypothalamic-pituitary-ovarian (HPO) axis, which is the major regulator of the female reproductive hormones: estrogen and progesterone. We begin by reviewing hypothalamic etiologies, including eating disorders and relative energy deficiency in sport. Then, pituitary causes of amenorrhea are reviewed, including hyperprolactinemia, empty sella syndrome, Sheehan's syndrome and Cushing's syndrome. Next, ovarian causes of amenorrhea are reviewed, including polycystic ovarian syndrome and primary ovarian insufficiency. Finally, other etiologies of amenorrhea are discussed, including thyroid disease, adrenal disease and reproductive tract anomalies. In conclusion, there is awide and diverse range of causes of amenorrhea in adolescents that originate from any level of the HPO axis, as well as anatomic and chromosomal etiologies. Treatment should be focused on the underlying cause. Preservation of bone density and risk of fractures should be discussed with amenorrheic patients since many causes of amenorrhea can result in decreased bone density and may be irreversible.

Low energy availability surrogates associated with lower bone mineral density and bone stress injury site

Exercise is an osteogenic stimulus that should increase bone mineral density (BMD) and protect against injury. However, some female athletes have lower BMD and increased bone stress injury (BSI) risk. Impaired bone health seen in athletes may be explained by low energy availability as described by concepts of Relative Energy Deficiency in Sport (RED-S) and Female Athlete Triad (Triad). To elucidate the relationship between RED-S/Triad risk factors and BSI to high-risk (femoral neck, sacrum) and low-risk (other) bones. Cross-sectional survey and retrospective chart review. Tertiary care academic center. Female athletes aged 15-30 years participating in ≥4h/week of exercise presenting to sports medicine/orthopedics clinic who had a self-reported BSI and available dual-energy x-ray absorptiometry (DXA) measurement of BMD. Not applicable. Location of BSI. In 127 athletes, high-risk BSI was associated with surrogates of low energy availability (p=.032) and having a DXA Z-score < -1 (p=.035) but not a current/past history of menstrual dysfunction (p=.348). Accumulating RED-S/Triad risk factors increase the odds of incurring a high-risk BSI (p=.048). Adolescent/young female athletes who sustain BSI at high-risk sites (femoral neck, sacrum) may have underlying risk factors (eg, low energy availability, poor overall bone health) that should prompt further workup and referral to optimize health in these athletes.

“This is the next frontier of performance”: power and knowledge in coaches “proactive” approaches to sportswomen’s health

ABSTRACT While research has explored coach knowledge on Low Energy Availability (LEA) and Relative Energy Deficiency in Sport (RED-S), this is the first paper to explore how coaches are responding in their practices. Drawing upon semi-structured interviews with high-performance and elite coaches, this paper focuses on the experiences, lessons learnt and methods of coaches who adopt “proactive” approaches with their sportswomen regarding LEA and RED-S)related topics. Engaging a feminist poststructural approach, we explore four key themes: (i) the initial impetus to change practices, (ii) challenges encountered, (iii) strategies developed in the process of improving their own and others knowledge of LEA, and (iv) the gendered reactions and experiences of creating change. Ultimately, adopting a feminist poststructuralist lens to examine coach “proactive” approaches to sportswomen’s health encourages a more critical exploration of the workings of power through knowledge and language within the highly gendered elite sport environment.

Is RED-S in athletes just another face of malnutrition?

Relative energy deficiency syndrome in sport (RED-S) can impair the function of several body systems, resulting in short and long-term threats to athletes' health and performance. Research showed that these health and performance problems are often unrecognized, and the treatment is not adequate. The retrospective study presented in this paper aims to determine the prevalence of RED-S-related symptoms in a sample of Slovenian competitive athletes from various sports. We performed retrospective research based on a database of 150 athletes, aged from 14 to 34, who had nutritional assessments as a part of their medical examination. Data were collected, refined and statistical analysis was performed. 77 women and 73 men were included; 113 were classified as young athletes (14-21 years) and 37 as elite athletes (more than 21 years). The majority (87%) of the athletes demonstrated at least one health-related symptom described by the RED-S-model; only 9% female and 18% male did not have any symptoms of RED-S. The number of different body systems with the compromised function was significantly higher (p<0.001) in female athletes (2.9±0.2) in comparison to male athletes (1.6±0.1). For other health-related symptoms, there are statistically significant differences between young and elite athletes (p=0.03), between female and male athletes (p=0.02) and between young and elite female athletes (p=0.01). When comparing groups by the number of all RED-S related symptoms, female athletes were more affected (p=0.02). According to the RED-S CAT tool, the majority of athletes (64%) were classified in the yellow group, 7% of athletes have severe health and performance problems and fulfil criteria for the red group, and only 29% were classified in the green group. A high prevalence of RED-S-related symptoms in our sample competitive athletes indicates the high prevalence of nutrition-related medical problems in young and elite athletes. Therefore, it is necessary to incorporate nutritional risk screenings as a part of regular medical examinations of athletes. In addition, appropriate treatments for competitive athletes should be readily accessible, even for young athletes. It seems that the youth athlete population is the most endangered for developing malnutrition-related health problems. At the same time, we urgently need a more specific and simple nutritional screening tool that will allow us to identify athletes at nutritional risk or athletes who have RED-S.

Lightweight rowers' perspectives of living with Relative Energy Deficiency in Sport (RED-S).

ObjectiveTo compete in lightweight rowing, strict limits are placed on the maximum body weight of each individual. As a result, lightweight rowers commonly restrict calorie intake despite high energy expenditure. This can result in Relative Energy Deficiency in Sport (RED-S). The aim of this study is to investigate the physical and psychosocial impact of RED-S, from the perspective of lightweight rowers.DesignSemi-structured individual qualitative interviews.ParticipantsAdults living in the United Kingdom who are current or former lightweight rowing participants and experienced ≥1 symptom of RED-S.MethodAudio-recorded semi-structured individual telephone interviews were performed. Data was analysed using an inductive thematic approach, coding was iterative and data-driven, facilitated by NVivo software.ResultsTwelve current or former lightweight rowers (intermediate to international standard, 67% female, aged 19–32 years) participated. Participants restricted calories and increased energy expenditure to elicit weight-loss in order to meet weight requirements. This resulted in psychosocial implications (reduced social interaction, difficulty maintaining relationships, poor emotional regulation, low mood, poor concentration, disordered eating, guilt and anxiety around food, and a negative body image). Some psychosocial implications persisted after retirement from lightweight rowing. Participants described a range of physical implications, including disrupted sleep, decreased performance and recovery, bowel disruption, menstrual dysfunction, fatigue, musculoskeletal pain, injury and weakened immune systems.ConclusionsThis study describes short and long-term physical and psychosocial impacts of RED-S from the perspective of lightweight rowers. Findings highlight the importance of effective RED-S prevention and management strategies for lightweight rowers. These findings may be used to educate health-care professionals, coaches and athletes on the personal impacts and serious health consequences of RED-S.

How Do We Assess Energy Availability and RED-S Risk Factors in Para Athletes?

Low energy availability (LEA) is considered to be the underlying cause of a number of maladaptations in athletes, including impaired physiological function, low bone mineral density (BMD), and hormonal dysfunction. This is collectively referred to as ‘Relative Energy Deficiency in Sport’ (RED-S). LEA is calculated through assessment of dietary energy intake (EI), exercise energy expenditure (EEE) and fat-free mass (FFM). The incidence of LEA in Paralympic athletes is relatively unknown; however, there are legitimate concerns that Para athletes may be at even higher risk of LEA than able-bodied athletes. Unfortunately, there are numerous issues with the application of LEA assessment tools and the criterion for diagnosis within the context of a Para population. The calculation of EEE, in particular, is limited by a distinct lack of published data that cover a range of impairments and activities. In addition, for several RED-S-related factors, it is difficult to distinguish whether they are truly related to LEA or a consequence of the athlete’s impairment and medical history. This narrative review outlines deficits and complexities when assessing RED-S and LEA in Para athletes, presents the information that we do have, and provides suggestions for future progress in this important area of sports nutrition.

Contributing Factors to Low Energy Availability in Female Athletes: A Narrative Review of Energy Availability, Training Demands, Nutrition Barriers, Body Image, and Disordered Eating.

Relative Energy Deficiency in sport is experiencing remarkable popularity of late, particularly among female athletes. This condition is underpinned by low energy availability, which is a byproduct of high energy expenditure, inadequate energy intake, or a combination of the two. Several contributing factors exist that may predispose an athlete to low energy availability, and therefore a holistic and comprehensive assessment may be required to identify the root causes. The focus of the current narrative review is to discuss the primary contributing factors as well as known risk factors for low energy availability among female athletes to help practitioners increase awareness on the topic and identify future areas of focus.

Defining ‘woman': A governmentality analysis of how protective policies are created in elite women's sport

Women's sport remains a contested realm that frequently features standards and regulations premised on women's inferiority and physiological distinctions from men. In response to these purported sex-based differences, a range of protective policies have been implemented to ostensibly ensure women's safety and health, defend “fair competition” in women's sport, and/or prevent the violation of social and medical boundaries that define who is a “woman.” Yet, protective policies encompass a multitude of rationales and strategies, demonstrating the malleability of “protection” in terms of who is protected and why. In this article, I draw from Michel Foucault's theory of “governmentality” to investigate the nuances of protective policies, especially their placed importance on sex differences. To do so, I examine three case studies: World Athletics’ (WA) 2019 female eligibility policy, WA's 2019 transgender eligibility policy, and the International Olympic Committee's (IOC) consensus statement on relative energy deficiency in sport (RED-S). Using document texts and semi-structured interviews with eight scientists involved with developing the case studies, I find that protective policies are developed through messy and often contentious processes that selectively draw from varying knowledges and discourses. This then culminates in contrasting methods of defining, protecting, and governing women athletes and their bodies.

Low Energy Availability and Relative Energy Deficiency in Sport: What Coaches Should Know

The Female Athlete Triad (Triad) and the more encompassing Relative Energy Deficiency in Sport (RED-S) are disorders caused by low energy availability (LEA). LEA is a state of insufficient energy intake by an athlete relative to their energy expenditure. Persistent LEA results in the deleterious consequences to health and performance that comprise RED-S. With respect to both the Triad and RED-S, researchers have called for more education of those involved with sport, particularly coaches, to help reduce the incidence of these disorders. Recent studies have shown that as few as 15% of coaches are aware of the Triad, with up to 89% unable to identify even one of its symptoms. RED-S is a more recently established concept such that coach knowledge regarding it has only begun to be assessed, but the results of these initial studies indicate similar trends as for the Triad. In this review, we synthesize research findings from 1986 to 2021 that pertains to LEA and RED-S, which coaches should know so they can better guide their athletes.

Improvement of Body Image Flexibility in Adolescent Female Athletes Undergoing Education about Nutrition and Body Image

Methods: A pre-post study was done measuring body image flexibility in adolescent female athletes. Athletes, aged 14-18, participated in educational sessions about nutrition, body image flexibility, and RED-S (relative energy deficiency in sport). Body image flexibility was measured by the BI-AAQ (Body Image - Acceptance and Action Questionnaire).

Beyond the Musculoskeletal System: Considering Whole-Systems Readiness for Running Postpartum

Background: Postpartum women frequently engage in running. In the absence of official guidance on returning-to-running postpartum, physical therapists rely on clinical experience alongside the available literature. Subsequently, the traditional evaluation of postpartum readiness for running tends to focus on musculoskeletal factors. This clinical commentary addresses how to evaluate and manage postpartum return-to-running in a systematic order by discussing relevant whole-systems considerations beyond the musculoskeletal system, while also highlighting possible interactions between relevant considerations. Discussion: Using a whole-systems biopsychosocial approach, physical therapists should consider the following when managing and evaluating readiness to return-to-running: physical deconditioning, changes to body mass, sleeping patterns, breastfeeding, relative energy deficiency in sport, postpartum fatigue and thyroid autoimmunity, fear of movement, psychological well-being, and socioeconomic considerations. Undertaking a risk-benefit analysis on a case-by-case basis using clinical reasoning to determine readiness to return-to-running postpartum should incorporate these considerations and their possible interactions, alongside considerations of a musculoskeletal evaluation and graded exercise progression. Conclusions: Return-to-running postpartum requires an individualized, whole-systems biopsychosocial approach with graded exercise progression, similar to the management of return to sport following musculoskeletal injuries. A video abstract for this article is available at:https://links.lww.com/JWHPT/A51

Relative energy deficiency in sport: modern approaches to diagnostics, treatment and prevention

In recent years, close attention has been paid to energy deficiency in professional athletes. More and more studies confirm the widespread prevalence of relative energy deficiency syndrome in sports and its relationship with various pathological conditions that lead to a decrease in the level of athletic performance. Nowadays the possibilities of early diagnosis and treatment of this syndrome are being carefully studied, and clinical protocols are being actively developed to facilitate the early detection of energy deficiency. The aim of the study was to summarize the modern data on the influence of the syndrome of relative energy deficiency in sports on the health and performance of athletes, as well as to consider effective methods for the diagnosis, treatment and prevention of this syndrome. Material and methods. The search was carried out using the Google Academy engine and electronic databases PubMed, MEDLINE, EMBASE, Scopus, Web of Science, eLIBRARY for the period from 2017 to 2021. For the search, we used keywords and their combinations: "relative energy deficit in sports", "female athlete triad", "menstrual dysfunction", "osteoporosis". Results. Based on our analysis, we can conclude that the syndrome of relative energy deficit in sports has a multicomponent negative effect on the athlete's organism and negatively affects his performance, well-being and sports results. Diagnosis of this condition is challenging due to the nonspecificity and variety of symptoms. Key diagnostic methods include physical examination, anamnesis gaining, dual energy X-ray absorptiometry, bioimpedance body composition analysis, and hormonal profile studies. Additional methods include: electrocardiography, study of the basal metabolic rate, hematological examination (hemoglobin, ferritin, etc.), determining the level of energy consumption using diaries of food and physical activity, determining blood vitamin level, etc. To facilitate the screening, diagnosis and follow-up of athletes, it is possible to use specially developed clinical protocols. Non-drug nutritional correction and optimal training plan are the main methods of treatment and prevention of energy deficiency. If this type of treatment is ineffective, hormone therapy should be considered. It is recommended to use transdermal estrogen therapy in combination with shortterm progestin therapy. In some cases, when very low bone mineral density or delayed fracture consolidation is detected, it is possible to use recombinant parathyroid hormone. Conclusion. Due to the relatively high prevalence of relative energy deficiency syndrome in athletes of both sexes and its long-term negative impact on athlete health and performance, further research is needed to improve the effectiveness of early diagnosis, prevention and treatment of pathological conditions associated with malnutrition.

Female military pentathlon athletes and scientific research - a mini-review

Aim: to compile existing information in the scientific literature on female military pentathlon athletes. Methods: searches were performed on Pubmed/Medline, Scielo, and Scholar Google databases with specific strings in English and Portuguese. Results: military pentathlon is a discipline that comprises five events, namely: rifle shooting, obstacle run, obstacle swimming, throwing, and cross country running. Our search initially identified 275 records, which were reduced to the final list of 14 after the eligibility criteria analysis was performed in two phases: title + abstract reading and full-text reading. The first record was published in 2007 (recent field of study) and most studies were cross-sectional ones (scarcity of experimental studies), investigating outcomes like psychological, anthropometric, biochemical, biomechanics, cardiopulmonary, nutritional, skin temperature, performance, and prevalence of injury. The female military pentathlon athletes present low values of body fat, energy intake, and high weekly training volume, so professionals must be aware to prevent relative energy deficiency in sports (RED-S) syndrome. The obstacle run was the most investigated event, with lower blood lactate and skin temperature for women athletes. It was also observed that anthropometric, muscle power, and cardiopulmonary variables are well correlated with athletic performance and in some studies, these correlations were stronger for female athletes. Conclusion: scientific research with female military pentathlon athletes is still incipient, especially for experimental design researches, which are highly encouraged in future studies.

Insufficient knowledge and inapproriate physiotherapy management of Relative Energy Deficiency in Sport (RED-S) in lightweight rowers

ObjectiveTo investigate the knowledge and management of Relative Energy Deficiency in Sport (RED-S), from the perspective of lightweight rowers and physiotherapists. DesignSemi-structured individual qualitative interviews. MethodsPhysiotherapists who had worked with lightweight rowers, and current and former lightweight rowers (who had experienced at least one symptom of RED-S), undertook audio-recorded semi-structured telephone interviews. An inductive thematic analysis was performed, facilitated by NVivo software. ResultsTwelve physiotherapists (n = 6 females, 1–20 years of experience managing lightweight rowers) and twelve lightweight rowers (n = 8 females, 1–8 years lightweight rowing experience, intermediate to elite/international level) were interviewed. Five key themes were identified: insufficient knowledge of RED-S, inadequate RED-S education, inappropriate management of RED-S, referral to other health professionals, prioritising performance over health. Participants provided suggestions for improving knowledge and management of RED-S in lightweight rowers, including formal physiotherapy education and training, and targeted education for athletes and coaches. ConclusionsThere was a significant lack of awareness of RED-S amongst physiotherapists and lightweight rowers. Most physiotherapists were not confident discussing or managing RED-S in athletes, and lightweight rowers were dissatisfied with the management they received. Improving RED-S education for physiotherapists and athletes may have important health implications for lightweight rowers.

“It's hard to find balance when you're broken”: Exploring female endurance athletes’ psychological experience of recovery from relative energy deficiency in sport (RED-S)

IntroductionThis study aimed to explore qualitatively the psychological experience of recovery from relative energy deficiency in sport (RED-S). More specifically, it sought to understand: how RED-S is experienced from a psychological perspective; sources of psychological conflict in the ongoing management of energy availability (EA); and athlete responses to psychological conflict in the pursuit of optimal EA. MethodsEight female endurance athletes identifying as “in recovery” or “recovered” from RED-S (M age = 29.78 years) participated in this integrated methods multiple case-study. Participants engaged in an initial topical life history interview, before completing an online diary over a 21-day period, taking photographs of psychological triggers for seven days, and participating in a follow-up interview. Data were analysed using reflexive thematic analysis. ResultsThe theme in too deep and treading water captured the significant psychological implications of RED-S. Seven sources of psychological conflict reported while managing EA were identified. The theme a constant tug of war represented the responses to these sources of psychological conflict in the ongoing management of EA. Within this theme, the subthemes in two minds and an emotional rollercoaster illustrated the cognitive and affective responses to psychological conflict, while giving in and the only way is through represented the adaptive and maladaptive behavioural responses during recovery, respectively. ConclusionThis study offers novel insights into the complex nature of recovery from RED-S and highlights the importance of considering psychological factors underpinning improved physiological functioning and overall wellbeing during RED-S recovery.

The relationship between disordered eating behaviors and injury rates in adolescent athletes.

To explore the relationship between disordered eating (DE) and significant sport injury in adolescent athletes. Responses to one item of the Disordered Eating Screen for Athletes and the Eating Attitudes Test (EAT-26) items, administered to n=308 adolescent athletes, were analyzed with data on injury. Nonparametric statistics and multiple regression analysis were used to examine differences in DE rates amongst known injured adolescent athletes. The EAT-26 scores of injured females, median score of 9, were significantly higher than all other groupings with H(3)=17.26 p < .001, η2 =.047. Using regression analyses, injury significantly predicted a rise in EAT-26 score by five points in females, p=.01, R2 =.052. This evidence suggests a relationship between adolescent female sport injury and DE, but no relationship between adolescent male sport injury and DE. These results demonstrate a need to screen for DE in athletes. Given a positive screen, athletes should be educated on the risks associated with relative energy deficiency and potentially referred to a practitioner with knowledge of the associated complications.

Prevalence of Surrogate Markers of Relative Energy Deficiency in Male Norwegian Olympic-Level Athletes

The syndrome of Relative Energy Deficiency in Sport (RED-S) includes wide-ranging effects on physiological and psychological functioning, performance, and general health. However, RED-S is understudied among male athletes at the highest performance levels. This cross-sectional study aimed to investigate surrogate RED-S markers prevalence in Norwegian male Olympic-level athletes. Athletes (n = 44) aged 24.7 ± 3.8years, body mass 81.3 ± 15.9kg, body fat 13.7% ± 5.8%, and training volume 76.1 ± 22.9hr/month were included. Assessed parameters included resting metabolic rate (RMR), body composition, and bone mineral density by dual-energy X-ray absorptiometry and venous blood variables (testosterone, free triiodothyronine, cortisol, and lipids). Seven athletes (16%) grouped by the presence of low RMR (RMRratio < 0.90) (0.81 ± 0.07 vs. 1.04 ± 0.09, p < .001, effect size 2.6), also showed lower testosterone (12.9 ± 5.3 vs. 19.0 ± 5.3nmol/L, p = .020) than in normal RMR group. In low RMRratio individuals, prevalence of other RED-S markers (-subclinical-low testosterone, low free triiodothyronine, high cortisol, and elevated low-density lipoprotein) was (N/number of markers): 2/0, 2/1, 2/2, 1/3. Low bone mineral density (z-score < -1) was found in 16% of the athletes, all with normal RMR. Subclinical low testosterone and free triiodothyronine levels were found in nine (25%) and two (5%) athletes, respectively. Subclinical high cortisol was found in 23% of athletes while 34% had elevated low-density lipoprotein cholesterol levels. Seven of 12 athletes with two or more RED-S markers had normal RMR. In conclusion, this study found that multiple RED-S markers also exist in male Olympic-level athletes. This highlights the importance of regular screening of male elite athletes, to ensure early detection and treatment of RED-S.

The Path Towards Progress: A Critical Review to Advance the Science of the Female and Male Athlete Triad and Relative Energy Deficiency in Sport.

Energy status plays a key role in the health of athletes and exercising individuals. Energy deficiency/low energy availability (EA), referring to a state in which insufficient energy intake and/or excessive exercise energy expenditure has resulted in compensatory metabolic adaptations to conserve fuel, can affect numerous physiological systems in women and men. The Female Athlete Triad, Male Athlete Triad, and Relative Energy Deficiency in Sport (RED-S) models conceptualize the effects of energy deficiency in athletes, and each model has strengths and limitations. For instance, the Female Athlete Triad model depicts relationships between low EA, reproductive, and bone health, underpinning decades of experimental evidence, but may be perceived as limited in scope, while the more recent RED-S model proposes a wider range of potential health effects of low EA, though many model components require more robust scientific justification. This critical review summarizes current evidence regarding the effects of energy deficiency on athlete healthby addressing the quality of the underlying science, the strengths and limitations of each model, and highlighting areas where future research is needed to advance the field. With the health and wellness of athletes and exercising individuals as the overarching priority, we conclude with specific steps that will help focus future research on the Female and Male Athlete Triad and RED-S, and encourage all researchers, clinicians, and practitioners to collaborate to support the common goal of promoting the highest quality science and evidence-based medicine in pursuit of the advancement of athletes' health, well-being, and performance.