Scoping review finds REDs guidelines still inconsistently applied in sports research

A scoping review of how researchers have applied guidelines for relative energy deficiency in sport (REDs) has found that, more than a decade after the International Olympic Committee first introduced the framework, the published literature remains strikingly inconsistent in its terminology, screening tools and use of clinical guidance. The review, published in Frontiers in Sports and Active Living, mapped thirty-two studies and concluded that most continued to anchor their work in the older Female Athlete Triad model, often in parallel with, rather than in place of, the IOC’s REDs guidelines.

REDs is a multifactorial syndrome arising from low energy availability (LEA), a mismatch between dietary energy intake and the energy expended on exercise and normal physiological processes. When energy intake is inadequate for the demands of training and everyday bodily function, athletes can develop a range of physiological, psychological and performance impairments. These include menstrual dysfunction, reduced bone mineral density, compromised musculoskeletal health such as an increased risk of bone stress injuries and impaired tissue repair, and disturbances in cardiovascular health. The concept was introduced by the IOC in 2014, expanding on the earlier Female Athlete Triad framework, which had been defined by the American College of Sports Medicine in 1992 and updated in 2007 as the interrelationship of disordered eating, menstrual dysfunction and osteoporosis in physically active females. The IOC updated its REDs model in 2018 and again in 2023, broadening its relevance to male athletes and providing more comprehensive clinical assessment and management guidance.

The research team, from Auckland University of Technology in New Zealand, conducted a systematic search of Medline, CINAHL, SPORTDiscus and Scopus on 21 September 2025, following the Preferred Reporting Items for Scoping Reviews. The search reached back to database inception and identified 3,023 records, from which thirty-two studies met the inclusion criteria. The included studies, published between 2008 and 2025, combined a total sample of 5,513 participants: 928 males, 4,164 females and 421 whose sex was not specified, comprising 1,785 professionals and 3,728 athletes. Consistent with scoping review methodology, the authors undertook no critical appraisal of study quality; the aim was to map the literature rather than evaluate it.

The terminology findings were among the review’s most consistent signals. Twenty-six of the included studies used mixed Triad, RED-S or REDs terminology, and twenty-six of the twenty-nine studies published after 2014 continued to use Triad-based terms. Nine studies were published after the 2023 IOC update introduced the hyphen-free “REDs” terminology, but only five of those adopted it. Twenty-five studies overall used mixed or parallel terminology, combining “Female Athlete Triad”, “RED-S” and “REDs” in various combinations. One study notably diverged from the conceptual shift altogether, explicitly rejecting the move toward REDs and retaining exclusive use of the term “Triad”. The authors interpret this overlapping vocabulary as characteristic of a conceptual transition phase in academic literature, in which newer frameworks take time to displace established ones.

Guideline application showed a similar pattern. Three studies predated the 2014 IOC consensus and followed the earlier Female Athlete Triad guidelines. Among the twenty-nine studies published after 2014, five followed the Triad framework alone, seventeen used Triad-based models in parallel with the 2014 and/or later IOC REDs guidelines, and five followed the IOC RED-S or REDs guidelines alone. A further two studies mentioned frameworks conceptually but did not operationalise any of them. Of the nine studies published in or after 2023, only four followed the 2023 REDs guidelines. The review’s authors stress that these patterns reflect application within research settings and should not be read as evidence of real-world clinical implementation or adherence in routine healthcare practice.

Screening tools told a comparable story of slow uptake. The Low Energy Availability in Females Questionnaire (LEAF-Q) was the most frequently referenced validated screening instrument, appearing in fifteen studies, but it has been validated only in female athletes, limiting its usefulness for identifying at-risk male and non-binary populations. The IOC’s original Clinical Assessment Tool (CAT), introduced in 2015, was referenced in only two studies, and just one study referred to the updated Clinical Assessment Tool version 2 (CAT2), despite its introduction in 2023. The CAT2 provides a structured framework for risk stratification and participation decision-making using a traffic light system, with the LEAF-Q and the male equivalent LEAM-Q forming its initial step. One included study, by Heikura and colleagues, was identified as the first empirical validation and field implementation of the 2023 IOC CAT2 framework in a large elite cohort, demonstrating that the updated tool can be applied in research settings even when minor methodological adaptations are needed.

Awareness of REDs varied enormously across the surveyed populations, ranging from 10 per cent to 92 per cent across samples. In a large multi-professional survey of 799 healthcare providers, only 22 per cent were aware of REDs, with awareness highest among sports medicine physicians at 92 per cent but far lower among orthopaedic surgeons (23 per cent), physiotherapists (18 per cent), gynaecologists (11 per cent) and general practitioners (10 per cent). In the same study, 57.6 per cent of providers felt competent discussing potential underlying issues, but only 7.4 per cent felt qualified to provide treatment. Another survey of sports medicine professionals found 76 per cent were aware of the Triad compared with 29 per cent aware of REDs, and participants felt more comfortable managing Triad cases (33 per cent) than REDs cases (13 per cent). Among athletes, awareness was similarly uneven: in a professional netball club, only one of thirteen athletes had heard of REDs and coaches reported no awareness, while pre-professional dancers showed comparatively higher awareness, with 73.4 per cent aware of LEA, 56.3 per cent aware of the Triad and 53.1 per cent aware of REDs.

The review also documented who was being studied. Twenty-six studies involved athlete participants, drawn disproportionately from female, elite, collegiate and endurance- or weight-sensitive sporting populations. Male athletes, para-athletes, recreational participants and team sport athletes were under-represented, which the authors note limits the generalisability of the evidence base. Nine studies examined healthcare professionals, including sports dietitians, physicians, physical therapists and athletic trainers, and three included both athletes and professionals. Across the studies that surveyed practitioners, awareness of the Female Athlete Triad was consistently higher than awareness of REDs, mirroring the terminology patterns in the research itself.

The authors are careful to frame their findings as a map of the literature rather than a verdict on clinical practice, and they identify several important limitations. Because eligibility required explicit citation of REDs, RED-S, Triad or LEA guidance, the evidence base is inherently skewed toward research already aligned with these frameworks, which likely inflates the apparent prevalence of guideline use and cannot estimate real-world uptake or non-adoption. Restricting inclusion to English-language publications may have introduced language bias, a single reviewer extracted the data, and no protocol was prospectively registered. Temporal comparisons warrant particular caution: studies are necessarily constrained by the guidelines available when they are designed and conducted, not when they are published. The review cites the example of one study that, despite being published after the 2023 framework’s release, could not report CAT2 scores because the tool was not yet active during its 2019 to 2022 data collection window.

Even with those caveats, the overall picture is of a persistent research-translation delay. The authors conclude that inconsistency in REDs terminology, screening and the operational use of guidelines is apparent across the literature, and they call for future research to prioritise the timely translation of emerging IOC guidance into study design. They argue that knowledge-translation efforts must better align emerging evidence, conceptual models and methodological design so that research can support standardised concepts, strengthen risk identification across diverse athlete populations and, ultimately, contribute to better athlete health outcomes.

Subject of Research: Inconsistent application of REDs guidelines, terminology and screening tools in sports medicine research

Article Title: Application of relative energy deficiency in sport (REDs) guidelines: a scoping review

Article References: McGahan, P. L., Carroll, M. R., & Molyneux, P. S. (2026). Application of relative energy deficiency in sport (REDs) guidelines: a scoping review. Frontiers in Sports and Active Living, 8, Article 1932921. https://doi.org/10.3389/fspor.2026.1932921

Image Credits: AI Generated

DOI: 10.3389/fspor.2026.1932921

Keywords: relative energy deficiency in sport, REDs, low energy availability, Female Athlete Triad, IOC consensus, scoping review, LEAF-Q, clinical assessment tool, athlete health, screening, sports nutrition, research translation