The Study
Overtraining Syndrome (OTS) and Relative Energy Deficiency in Sport (RED-S): Shared Pathways, Symptoms and Complexities
This study is like a teacher summarizing what other scientists have found. It doesn’t do a new experiment but looks at old ones and says, 'Hey, these two problems in athletes seem to look a lot alike.' We can learn from it, but it doesn’t prove why or how things happen.
Analysis score
Maximum 5 for a narrative review.
Where the score came from
Sometimes athletes feel super tired and worn out, and people think they are training too much. But this review says the real reason might be that they're not eating enough food, especially carbs, to fuel their workouts.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 51 / 100
Quality score
Based on clinical experience or non-systematic literature reviews. The lowest level of evidence as they are most susceptible to bias and personal perspective.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, this is important because athletes might be misdiagnosed with overtraining when they just need to eat more, especially during heavy training.
- 286 out of 100 studies that looked at tired athletes found they weren’t eating enough energy or carbs.
- 3Most symptoms of overtraining are also symptoms of not fueling right.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Sports Medicine
Year
2021
Authors
T. Stellingwerff, I. Heikura, R. Meeusen, S. Bermon, S. Seiler, M. Mountjoy, L. Burke
Related Content
Claims (4)
If athletes don’t eat enough calories or carbs, especially during intense training, they might not recover well—and fixing that could stop them from feeling overly tired or burned out, which people often think is overtraining.
If athletes train too much and don’t eat enough, they might be misdiagnosed with overtraining when the real issue is low energy from not fueling properly.
Most studies on overtrained endurance athletes found they weren’t eating enough carbs or energy when their symptoms started — so running low on fuel might be a common factor.
Not eating enough calories can make you feel like you're overtraining, but you can still overtrain even if you're eating enough food and protein.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.