Exercise-Induced Physiological Fatigue in Horses: Review

Abstract

Horses that become fatigued either stop exercising or continue exercising but at a lower intensity. The researches show that there are many causes of exercise induced fatigue. The depletion of energy stores and accumulation of metabolites during muscle contraction are considered as the important factors causing fatigue. Furthermore, generated heat during muscle contraction impairs the fluid, electrolyte and acid-base balances of internal environment of horse body. The occurrence of physiological fatigue differs according to the type of exercise the horse is performing. The intensity and the duration of the exercise are very important parameters during the onset of fatigue. The onset of fatigue in flat racing horses is completely different physiological phenomenon to fatigue in endurance horses performing with low intensity but long duration exercise. In this review we focus on the underlying physiological mecha