Overtraining Syndrome in Athletes: A Comprehensive Review and Novel Perspectives

1. Introduction

2. Historical perspective

3. Basic concepts on overtraining syndrome

4. Classical understanding of overtraining syndrome

a. Initial theories

b. Preliminary biomarkers:

- Biochemical markers

- Clinical markers

c. Current diagnostic criteria

5. Methodological challenges and limitations of the research of overtraining syndrome

6. (New findings on overtraining syndrome)

a. Advances in the methodology

b. Lessons from the Endocrine and Metabolic Responses on Overtraining Syndrome (EROS) study

B1. Summary of the results

B2. Analysis of the results: the mechanisms and aspects unveiled by the EROS study

B3. Remarkable, unexpected, and novel findings

c. New markers of overtraining syndrome

d. Novel disruptors of OTS, predictors of clinical and biochemical behaviors, and correlations between clinical and metabolic parameters

e. Novel risk factors for OTS

The EROS STUDY as a shift in the understanding of overtraining syndrome

7. New understanding on overtraining syndrome

a. From an overtraining-centered to a multi-factorial understanding of OTS

b. The pivotal sequence of dysfunctions that leads to OTS

c. Overtraining syndrome: an overt or a relative dysfunction'

d. Unexpected serendipitous findings of novel conditioning processes in healthy athletes

e. The novel key pathophysiological characteristic of overtraining syndrome

f. New concepts on overtraining syndrome

g. Particularities of the diagnosis of overtraining syndrome in female athletes

8. Similarities between Overtraining Syndrome (OTS), Female Athlete Triad (TRIAD), Relative Energy Deficiency of the Sport (RED-S), and Burnout syndrome of the athlete (BSA)

a. Female Athlete Triad (TRIAD)

b. Relative Energy Deficiency of the Sport (RED-S)

c. Burnout Syndrome of the Athlete (BSA)

d. Similarities between RED-S/TRIAD, BSA, and OTS/PDS

9. The high prevalence of pseudo-OTS

10. Deconditioning and hypometabolism as two neologisms that describe the novel processes identified in OTS

11. Practical approach to the athlete suspected or at high-risk for OTS

a. New diagnostic tools for OTS

b. Preliminary core for the diagnosis of OTS

c. Tools for the identification of athletes at high risk for OTS

d. Advances in the diagnosis of OTS

e. Effective prevention of overtraining syndrome