RED-S: causes, impacts, and prevention

RED-S: causes, impacts, and prevention

Always feeling tired, weak, and like your performance isn’t where it should be? If yes, you might be experiencing the symptoms of Relative Energy Deficiency in Sport (RED-S). 

Major sports organizations, including the International Olympic Committee, are committing to bringing attention to RED-S. Here’s a quick run down of what causes this deficiency and what athletes should be concerned about:

RED-S happens when the body is struggling to support basic functions because of low energy availability (LEA), either chronically over many weeks/months or severely over a few days. This is caused by not eating enough calories and can be influenced by disordered eating and body image issues.

The impacts of RED-S include:

    • Impaired performance: increased fatigue, decreased muscle strength, protein synthesis, endurance, coordination, concentration, and training response
    • Reproductive health: period loss and reduced fertility
    • Hormone health: decreases in growth hormones and female sex hormones, increases in cortisol which impacts mood
    • Bone health: loss of bone density which increases injury risk
    • Immune system: possible increase in infection risk

Busy athletes, like college athletes, may be at even greater risk because of difficulty prioritizing nutrition. In fact, over half of NCAA female soccer athletes demonstrate signs of LEA. The high prevalence of LEA may be because many athletes believe that lower body weight will increase performance or because of pressure from coaches/teammates to look a certain way. Access to nutritional support and education, especially for pre- and post-workout fueling, may be a way to help prevent athletes from underfueling and keep them performing their best. 

If you notice any symptoms of RED-S, including loss of a period (amenorrhea), fatigue, rapid body weight loss, mood disturbances, hair loss, or frequent illness, speak to a nutritionist or medical professional to ensure that your body is receiving the nutrients it needs.

By Carlyn Johnson


Cabre, H. E., Moore, S. R., Smith-Ryan, A. E., & Hackney, A. C. (2022). Relative Energy Deficiency in Sport (RED-S): Scientific, Clinical, and Practical Implications for the Female Athlete. Deutsche Zeitschrift fur Sportmedizin, 73(7), 225–234.

Jagim, A. R., Fields, J., Magee, M. K., Kerksick, C. M., & Jones, M. T. (2022). Contributing Factors to Low Energy Availability in Female Athletes: A Narrative Review of Energy Availability, Training Demands, Nutrition Barriers, Body Image, and Disordered Eating. Nutrients, 14(5), 986.

Ioc. (2023, September 28). IOC publishes new consensus statement on Relative Energy Deficiency in sport (reds) to protect athlete health. International Olympic Committee.,REDs%20 

Magee, M. K., Lockard, B. L., Zabriskie, H. A., Schaefer, A. Q., Luedke, J. A., Erickson, J. L., Jones, M. T., & Jagim, A. R. (2020). Prevalence of Low Energy Availability in Collegiate Women Soccer Athletes. Journal of functional morphology and kinesiology, 5(4), 96. 

Relative energy deficiency in sport (red-S). Boston Children’s Hospital. (n.d.).,increased%20risk%20of%20injury 

Wasserfurth, P., Palmowski, J., Hahn, A. et al. (2020). Reasons for and Consequences of Low Energy Availability in Female and Male Athletes: Social Environment, Adaptations, and Prevention. Sports Med - Open, 6(44).

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