Nutritional aspects of post exercise skeletal muscle glycogen synthesis in horses: a comparative review.
Authors: Waller A P, Lindinger M I
Journal: Equine veterinary journal
Summary
Muscle glycogen depletion during intense or endurance exercise is a fundamental concern in equine nutrition, yet horses recover glycogen stores substantially more slowly than humans or rodents—a critical distinction that has often been overlooked in practice. Waller and Lindinger's 2010 comparative review examined the mechanistic differences in carbohydrate metabolism across species, revealing that equine muscle glycogen synthesis proceeds at only 2–3 times slower rate than in humans and rats, even when horses receive high-soluble carbohydrate diets designed to maximise glycogen repletion. Beyond highlighting these inherent species differences in glucose uptake and utilisation, the authors explored why conventional human sports nutrition protocols prove ineffective for horses and evaluated alternative nutritional strategies—including protein supplementation, medium- and long-chain fatty acid provision, and strategic rehydration—as means to support recovery between workloads. The findings challenge the widespread assumption that feeding soluble carbohydrates alone will adequately restore muscle glycogen in horses, suggesting instead that a more nuanced, species-appropriate approach incorporating multiple macronutrient sources and hydration status may be necessary to optimise post-exercise recovery. For equine practitioners—whether nutritionists formulating competition feeds, veterinarians managing exercise-related fatigue, or farriers and physiotherapists supporting working horses—this review reinforces that equine metabolic handling of carbohydrates fundamentally differs from other species, demanding evidence-based feeding strategies tailored specifically to equine physiology rather than extrapolated from human or rodent models.
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Practical Takeaways
- •High soluble carbohydrate feeding protocols developed for humans may not be effective for post-exercise glycogen repletion in horses due to fundamental metabolic differences
- •Consider multi-modal nutritional approaches including protein supplementation, fatty acids, and adequate rehydration rather than relying solely on carbohydrate loading
- •Recovery nutrition strategies should be species-specific; standardized human protocols should not be automatically applied to equine training and competition programs
Key Findings
- •Muscle glycogen synthesis in horses is 2-3 fold slower than in humans and rats despite high soluble carbohydrate diets
- •Significant species differences exist in carbohydrate uptake and utilisation between horses and other mammals
- •Many conclusions from human exercise physiology do not directly apply to equine athletes
- •Alternative feeding strategies including protein, fatty acids, and rehydration may optimize post-exercise recovery in horses