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Unexplained underperformance syndrome in sport horses: classification, potential causes and recognition
J L L Rivero1, E van Breda, C W Rogers
1Muscular Biopathology Laboratory, Department of Comparative Anatomy and Pathological Anatomy, Faculty of Veterinary Sciences, University of Cordoba, Cordoba, Spain.
Equine Veterinary Journal
|March 22, 2008
Summary
Overtraining syndrome (OTS) in horses results from inadequate training and recovery, causing performance loss. The hypothalamo-pituitary-adrenocortical axis dysfunction is a potential cause, but more research is needed for diagnostic tools.
Area of Science:
- Equine Sports Medicine
- Animal Physiology
- Veterinary Science
Background:
- Overtraining syndrome (OTS) in horses is characterized by performance reduction and chronic maladaptation due to insufficient training stress and recovery.
- It is crucial to differentiate OTS from over-reaching, a condition with a shorter recovery period.
- The exact mechanisms of OTS remain poorly understood, with no established objective biomarkers.
Purpose of the Study:
- To investigate the underlying mechanisms of overtraining syndrome (OTS) in horses.
- To explore potential diagnostic tools and differentiate OTS from over-reaching.
- To identify factors contributing to OTS beyond training and recovery imbalances.
Main Methods:
- Review of scientific literature on equine overtraining syndrome.
- Analysis of the role of the hypothalamo-pituitary-adrenocortical axis.
- Assessment of diagnostic approaches including history, clinical signs, and standardized exercise tests.
Main Results:
- Red cell hypervolaemia is not a mechanism for OTS in horses.
- Hypothalamo-pituitary-adrenocortical axis dysfunction is currently the most implicated mechanism.
- Diagnosis relies on thorough assessment of history, performance deficit, and behavioral changes, as objective biomarkers are lacking.
Conclusions:
- OTS in horses is a complex condition primarily caused by an imbalance between training and recovery.
- While hypothalamo-pituitary-adrenocortical axis dysfunction is a potential factor, further research is required.
- Standardized exercise tests may aid in detecting early overtraining by monitoring hormonal responses, but longitudinal studies are needed to validate their predictive potential.
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