Review of the scientific rationale, development and validation of the International Olympic Committee Relative Energy Deficiency in Sport Clinical Assessment Tool: V.2 (IOC REDs CAT2)—by a subgroup of the IOC consensus on REDs

Abstract

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.

Body dissatisfaction, disordered eating and exercise behaviours: associations with symptoms of REDs in male and female athletes

“…Impaired haematological function is among potential consequences of REDs 4 32. In accordance with this, we found positive associations between serum iron and testosterone, and inverse associations between TIBC and testosterone.…”

“…Further data inspection revealed that two out of three females with RMR <30 kcal/kg FFM/day scored well above the LEAF-Q total cut-off. While RMR/FFM has been suggested as a potential marker of REDs, the evidence is somewhat conflicting 32. A potential reason for some of the discrepancies encountered in this and similar studies is the sport-specific validity of LEAF-Q and its subscales.…”

“…Clinically to subclinically low testosterone is among the primary indicators included in REDs CAT2 32. No participant in this study had clinically low levels, but two athletes fell into what has previously been referred to as subclinical ‘grey zone’ (8–12 nmol/L) 37…”

“…The EAI questionnaire was used to screen for compulsive exercise, as it has been used in similar studies on REDs,12 and IOC has listed it among potential instruments for initial screening of REDs 4 32. An ongoing debate exists on terminology and applicability of tools and cut-offs used to screen for exercise addiction/compulsive exercise behaviours in athletic populations.…”

“…One additional measure (female) was excluded from the RMR analysis due to technical issues. IOC has listed RMR <30 kcal/kg fat-free mass (FFM)/day as a potential indicator of REDs 32…”