Mitochondrial Adaptations to Exercise Training in Equine Skeletal Muscle: A Narrative Review

Area of Science:

• Equine Exercise Physiology
• Mitochondrial Biology
• Skeletal Muscle Metabolism

Background:

• Horses are highly specialized athletic mammals with remarkable metabolic adaptability in skeletal muscle.
• Mitochondria are crucial for energy production, regulating oxidative phosphorylation and cellular responses to exercise stress.

Purpose of the Study:

• To review current evidence on exercise-induced mitochondrial remodeling in equine skeletal muscle.
• To synthesize findings from equine, human, and rodent studies.

Main Methods:

• Comprehensive literature search across PubMed, Web of Science, and Scopus.
• Inclusion of peer-reviewed original research and review articles on equine exercise physiology, mitochondrial biology, and skeletal muscle metabolism.

Main Results:

• Training induces mitochondrial adaptations like biogenesis, improved oxidative phosphorylation, and metabolic flexibility.
• Studies show increased mitochondrial density and respiratory capacity in trained horses, enhancing performance.
• Mitochondrial plasticity is linked to muscle fiber type and regulated by pathways like AMPK and PGC-1α.

Conclusions:

• Exercise significantly remodels equine skeletal muscle mitochondria, improving aerobic capacity and delaying fatigue.
• While adaptations are evident, direct mechanistic evidence in horses is limited.
• Further standardized longitudinal studies are necessary to fully understand these adaptations in horses.