dumbbells, apples, a bottle, nuts and a skipping rope in a row

Project: Relative Energy Deficiency in Sports (the REI project)

Relative Energy Deficiency in Sports (RED-S) is a syndrome that affects both health and physiological function. It is common in sports with high training volumes and weight focus. We aim to investigate the prevalence of RED-S within Swedish sports, how the sport environment can be preventive, how RED-S affects physiological functions during the athletic career, as well as health effects later in life.

Project information

Project manager
Anna Melin
Other project members
Madeleine Ahlgren, Jørgen Kjær, Susanne Linnér, Camilla Mohlin, Per Nilsson, Peter Pagels, Haris Pojskic, Thony Ragnarsson, Kristina Tryselius and Cornelia Witthöft, Linnaeus University; Klara Edlund, Sofiahemmet/Karolinska Institutet; all Sweden
Participating organizations
Linnaeus University
The Swedish Research Council for Sport Science, the Swedish Olympic Committee, WADA (World Anti-Doping Agency, Linnaeus University
1 March 2022–1 June 2024
Sport Science (Department of Sport Science, Faculty of Social Sciences)

More about the project

Relative Energy Deficiency in Sports (RED-S; REI in Swedish) is a syndrome that affects both health and performance, RED-S is common in sports with high training volumes, such as endurance disciplines, and in weight-focused sports, such as aesthetic disciplines.

The underlying cause is long-term low energy intake in relation to training volume. Low energy availability can occur, among other things, due to insufficient appetite, insufficient knowledge about sports nutrition, or an eating disorder.

Prolonged low energy availability causes, among other things, hormonal alterations, reduced protein synthesis and fertility, increased risk of injuries, impaired bone health, and negative effects on performance. Other frequent symptoms of RED-S are gastrointestinal dysfunction, hypoglycemia, hypotension and dyslipidemia. Therefore, athletes may have a stable body weight within the normal range but at the same time have RED-S with low libido/menstrual dysfunction, with increased risk of illness, injuries and reduced performance.  

The aim with the REI study is to investigate the prevalence of RED-S with and without eating disorders within Swedish sport, how it affects physiological functions and nutritional status during the athletic career, but also potential health effects later in life. We also aim to investigate how different aspects within the sport environments may have preventive effects of the development of RED-S and eating disorders.

The project is part of the research in the Sustainable sport, performance and leadership research group and the Linnaeus Knowledge Environment Sustainable Health.