UNASSIGNED: The review aims to summarize the markers used in diagnosing relative energy deficiency in sport (REDs) and compare them with the REDs CAT2 score.
UNASSIGNED: A systematic search was performed in the PubMed, Web of Science, and SPORTDiscus databases during April 2023. The descriptors used were \"athlete\" AND \"REDs,\" along with respective entry terms. The selection process followed the PRISMA 2020 recommendations, identifying 593 records, from which 13 studies were ultimately selected. Seventy-nine markers were identified and categorized into six groups: bone mineral density (BMD), metabolic resting rate, blood biomarkers, anthropometrics, nutritional intake, and performance parameters. The most frequently utilized biomarkers included BMD, anthropometric parameters (e.g., body mass index, body mass, and fat mass), and the triiodothyronine (T3) concentration.
UNASSIGNED: According to the REDs CAT2 pointed indicators, the biomarkers varied among the studies, while 7 out of the 13 included studies achieved a ≥60% agreement rate with this tool. The prevalence of low energy availability, an etiological factor in the development of REDs, was detected in 4 out of 13 studies, with an average of 39.5%.
UNASSIGNED: In conclusion, this review highlights the most commonly used markers in diagnosing REDs, such as BMD, anthropometric parameters, and T3 hormone concentration. Due to the current inconsistencies, standardizing diagnostic methodologies is crucial for future research. By focusing on widely used markers, this review aids future research planning and result interpretation and points out the ongoing need for methodological consistency in evolving diagnostic tools.
UNASSIGNED: https://www.crd.york.ac.uk/, PROSPERO (CRD42022320007).

OBJECTIVE: To summarize and describe risk factors for running-related injuries (RRIs) among high school and collegiate cross-country runners. DESIGN: Descriptive systematic review. LITERATURE SEARCH: Four databases (Scopus, SPORTDiscus, CINAHL, Cochrane) were searched from inception to August 2023. STUDY SELECTION CRITERIA: Studies assessing RRI risk factors in high school or collegiate runners using a prospective design with at least 1 season of follow-up were included. DATA SYNTHESIS: Results across each study for a given risk factor were summarized and described. The NOS and GRADE frameworks were used to evaluate quality of each study and certainty of evidence for each risk factor. RESULTS: Twenty-four studies were included. Overall, study quality and certainty of evidence were low to moderate. Females or runners with prior RRI or increased RED-S (relative energy deficiency in sport) risk factors were most at risk for RRI, as were runners with a quadriceps angle of >20° and lower step rates. Runners with weaker thigh muscle groups had increased risk of anterior knee pain. Certainty of evidence regarding training, sleep, and specialization was low, but suggests that changes in training volume, poorer sleep, and increased specialization may increase RRI risk. CONCLUSION: The strongest predictors of RRI in high school and collegiate cross-country runners were sex and RRI history, which are nonmodifiable. There was moderate certainty that increased RED-S risk factors increased RRI risk, particularly bone stress injuries. There was limited evidence that changes in training and sleep quality influenced RRI risk, but these are modifiable factors that should be studied further in this population. J Orthop Sports Phys Ther 2024;54(2):1-13. Epub 16 November 2023. doi:10.2519/jospt.2023.11550.

The purpose of this narrative review is to identify health and performance consequences associated with LCA in female endurance athletes. The intake of carbohydrates (CHO) before, during, and after exercise has been demonstrated to support sport performance, especially endurance activities which rely extensively on CHO as a fuel source. However, low energy availability (LEA) and low carbohydrate availability (LCA) are common in female athletes. LEA occurs when energy intake is insufficient compared to exercise energy expenditure, and LEA-related conditions (e.g., Female Athlete Triad (Triad) and Relative Energy Deficiency in Sport (RED-S)) are associated with a myriad of health and performance consequences. The RED-S model highlights 10 health consequences and 10 performance consequences related to LEA. The independent effect of LCA on health and performance has been under-researched, despite current CHO intake being commonly insufficient in athletes. It is proposed that LCA may not only contribute to LEA but also have independent health and performance consequences in athletes. Furthermore, this review highlights current recommendations for CHO intake, as well as recent data on LCA prevalence and menstrual cycle considerations. A literature review was conducted on PubMed, Science Direct, and ResearchGate using relevant search terms (i.e., \"low carbohydrate/energy availability\", \"female distance runners\"). Twenty-one articles were identified and twelve met the inclusion criteria. The total number of articles included in this review is 12, with 7 studies illustrating that LCA was associated with direct negative health and/or performance implications for endurance-based athletes. Several studies included assessed male athletes only, and no studies included a female-only study design. Overall, the cumulative data show that female athletes remain underrepresented in sports science research and that current CHO intake recommendations and strategies may fail to consider female-specific adaptations and hormone responses, such as monthly fluctuations in estrogen and progesterone throughout the menstrual cycle. Current CHO guidelines for female athletes and exercising women need to be audited and explored further in the literature to support female athlete health and performance.

In the past decade, the study of relationships among nutrition, exercise and the effects on health and athletic performance, has substantially increased. The 2014 introduction of Relative Energy Deficiency in Sport (REDs) prompted sports scientists and clinicians to investigate these relationships in more populations and with more outcomes than had been previously pursued in mostly white, adolescent or young adult, female athletes. Much of the existing physiology and concepts, however, are either based on or extrapolated from limited studies, and the comparison of studies is hindered by the lack of standardised protocols. In this review, we have evaluated and outlined current best practice methodologies to study REDs in an attempt to guide future research.This includes an agreement on the definition of key terms, a summary of study designs with appropriate applications, descriptions of best practices for blood collection and assessment and a description of methods used to assess specific REDs sequelae, stratified as either Preferred, Used and Recommended or Potential Researchers can use the compiled information herein when planning studies to more consistently select the proper tools to investigate their domain of interest. Thus, the goal of this review is to standardise REDs research methods to strengthen future studies and improve REDs prevention, diagnosis and care.

BACKGROUND: The assessment of body composition (BC) in sport raises concern for athlete health, especially where an overfocus on being lighter or leaner increases the risk of Relative Energy Deficiency in Sport (REDs) and disordered eating.
METHODS: We undertook a critical review of the effect of BC on performance (29 longitudinal, prospective or intervention studies) and explored current practice related to BC considerations via a follow-up to a 2013 internationally distributed survey.
RESULTS: The review found that a higher level of body fat was negatively associated with endurance performance, while a gain in muscle mass resulted in performance benefits across sports. BC did not contribute to early talent identification, and no unique cut-off to signify a performance advantage for BC was identified. BC appears to be one of an array of variables impacting performance, and its influence should not be overstated. The survey (125 practitioners, 61 sports and 26 countries) showed subtle changes in BC considerations over time, such as an increased role for sport dietitian/nutrition practitioners as BC measurers (2013: 54%, 2022: 78%); less emphasis on reporting of body fat percentage (2013: 68%, 2022: 46%) and reduced frequency of BC assessment if ≥every fourth week (2013: 18%, 2022: 5%). Respondents remained concerned about a problematic focus on BC (2013: 69%, 2022: 78%). To address these findings, we provide detailed recommendations for BC considerations, including an overview of preferable BC methodology.
CONCLUSIONS: The \'best practice\' guidelines stress the importance of a multidisciplinary athlete health and performance team, and the treatment of BC data as confidential medical information. The guidelines provide a health focus around BC, aiming to reduce the associated burden of disordered eating, problematic low energy availability and REDs.

Overall athlete health is a stated priority by the International Olympic Committee (IOC), yet it can be difficult for athletes to safely balance nutritional needs, training load, recovery, social interactions, expectations and other demands. The effect of energy intake and, especially, low energy availability (LEA) on athlete mental health, is understudied. In this narrative review, we examine research that has included psychological factors and mental health variables when investigating the effect of LEA, dieting/restrictive eating and Relative Energy Deficiency in Sport (REDs), since the 2018 IOC consensus statement on REDs. Based on currently available data, early psychological indicators associated with problematic LEA are mood changes, fatigue and psychological conflict. More severe mental health outcomes associated with REDs are reduced well-being, elevated anxiety, depressive symptoms and eating disorders. We propose a psychological model that helps structure how possible risk factors (eg, body dissatisfaction, environmental demands or increased training load) and moderating (eg, gender, sport) and/or potential mediating (eg, social climate, self-esteem) factors are associated with LEA and ultimately REDs. The current scientific literature underscores the importance of including mental health factors when screening for REDs and for developing a clinical approach to address the psychological sequelae of REDs once diagnosed. An interdisciplinary perspective is recommended. Lastly, and importantly, the athlete perspective urges clinicians to not underestimate the drive for success and denial of health consequences that athletes demonstrate when pursuing their sport goals.

Relative Energy Deficiency in Sport (REDs) is common among female and male athletes representing various sports at different performance levels, and the underlying cause is problematic low energy availability (LEA). It is essential to prevent problematic LEA to decrease the risk of serious health and performance consequences. This narrative review addresses REDs primary, secondary and tertiary prevention strategies and recommends best practice prevention guidelines targeting the athlete health and performance team, athlete entourage (eg, coaches, parents, managers) and sport organisations. Primary prevention of REDs seeks to minimise exposure to and reduce behaviours associated with problematic LEA. Some of the important strategies are educational initiatives and de-emphasising body weight and leanness, particularly in young and subelite athletes. Secondary prevention encourages the early identification and management of REDs signs or symptoms to facilitate early treatment to prevent development of more serious REDs outcomes. Recommended strategies for identifying athletes at risk are self-reported screening instruments, individual health interviews and/or objective assessment of REDs markers. Tertiary prevention (clinical treatment) seeks to limit short-term and long-term severe health consequences of REDs. The cornerstone of tertiary prevention is identifying the source of and treating problematic LEA. Best practice guidelines to prevent REDs and related consequences include a multipronged approach targeting the athlete health and performance team, the athlete entourage and sport organisations, who all need to ensure a supportive and safe sporting environment, have sufficient REDs knowledge and remain observant for the early signs and symptoms of REDs.

Relative Energy Deficiency in Sport (REDs) has various different risk factors, numerous signs and symptoms and is heavily influenced by one\'s environment. Accordingly, there is no singular validated diagnostic test. This 2023 International Olympic Committee\'s REDs Clinical Assessment Tool-V.2 (IOC REDs CAT2) implements a three-step process of: (1) initial screening; (2) severity/risk stratification based on any identified REDs signs/symptoms (primary and secondary indicators) and (3) a physician-led final diagnosis and treatment plan developed with the athlete, coach and their entire health and performance team. The CAT2 also introduces a more clinically nuanced four-level traffic-light (green, yellow, orange and red) severity/risk stratification with associated sport participation guidelines. Various REDs primary and secondary indicators have been identified and \'weighted\' in terms of scientific support, clinical severity/risk and methodological validity and usability, allowing for objective scoring of athletes based on the presence or absence of each indicator. Early draft versions of the CAT2 were developed with associated athlete-testing, feedback and refinement, followed by REDs expert validation via voting statements (ie, online questionnaire to assess agreement on each indicator). Physician and practitioner validity and usability assessments were also implemented. The aim of the IOC REDs CAT2 is to assist qualified clinical professionals in the early and accurate diagnosis of REDs, with an appropriate clinical severity and risk assessment, in order to protect athlete health and prevent prolonged and irreversible outcomes of REDs.

There are many immediate and longer-term physical, psychological and metabolic benefits of being active during adolescence. These benefits exist when exercise and physical activity are undertaken in a state of energy balance. When exercise occurs in an environment of low energy availability, this is currently termed relative energy deficiency in sport and there are potential significant negative effects on mental well-being, bone, endocrine and metabolic health. Therefore, relative energy deficiency in sport may present to many different specialists or allied health professionals depending upon the symptoms or reasons for seeking help, which include injury, such as bone stress or soft tissue problems, irregular or absent menstruation, stress, anxiety or low mood, or sporting underperformance as examples. The promotion of physical activity in adolescence is a critical part of public health strategy. In parallel with this positive public health message, there needs to be an increase in the awareness of, and education about, relative energy deficiency in sport for those working with and looking after adolescents.This review provides an up to date, practical evidenced based guide on the recognition, investigation and management of relative energy deficiency in sport in the adolescent, both male and female.

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 health by 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.