Relative Energy Deficiency in Sport Explained: Causes, Symptoms, and How to Recover from REDs
This week, Zoë and Kylee dig into one of the most misunderstood topics in endurance sports: RED-S , Relative Energy Deficiency in Sport. We break down what it actually is (spoiler: it’s not just “overtraining”), how to recognize early warning signs, and what the latest science says about recovery.
From the old-school concept of the female athlete triad to the 2024 “Does RED-S Exist?” paper, we trace how the conversation around under-fueling has evolved, and why so many athletes are still falling through the cracks. We’ll unpack how RED-S affects everything from hormones and metabolism to bone density, mood, and performance, and why it doesn’t just happen to women or elite runners.
This episode separates evidence from internet rumor and offers real talk on what it takes to recover: eating enough, resting enough, and understanding that being tired, cold, and cranky isn’t “just part of training.” Whether you’re an endurance athlete chasing PRs or someone just trying to feel good in your body again, this one’s for you.
References:
Mountjoy, M., Ackerman, K. E., Bailey, D. M., Burke, L. M., Constantini, N., Hackney, A. C., … Verhagen, E. (2023). International Olympic Committee’s (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine, 57(17), 1073–1097. https://doi.org/10.1136/bjsports-2023-106994
Stellingwerff, T., Mountjoy, M., McCluskey, W. T. P., Ackerman, K. E., Verhagen, E., Heikura, I. A., … et al. (2023). 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). British Journal of Sports Medicine. https://doi.org/10.1136/bjsports-2023-106914
Jeukendrup, A. E., Areta, J. L., Van Genechten, L., Langan-Evans, C., Pedlar, C. R., Rodas, G., … Walsh, N. P. (2024). Does relative energy deficiency in sport (REDs) syndrome exist? Sports Medicine, 54, 2793–2816. https://doi.org/10.1007/s40279-024-02108-y
Areta, J. L., Jeukendrup, A. E., Van Genechten, L., Langan-Evans, C., Pedlar, C. R., Rodas, G., … Walsh, N. P. (2025). Limited empirical support for relative energy deficiency in sport (REDs) syndrome. Sports Medicine, 55(8), 2051–2055. https://doi.org/10.1007/s40279-025-02220-7
Ackerman, K. E., Palacios, C., Lambert, M. I., & others. (2023). Methodology for studying Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine, 57(17), 1136–1144. https://bjsm.bmj.com/content/bjsports/57/17/1136.full.pdf