1. Effects of physical stress on the systems of the horse

2. Stress. – Positive stress – Excessive stress Positive stress allows adaptation, e.g. adaptation of muscles, remodelling of bones. Temporary stress, e.g. sweating, agitation. Excessive stress, e.g. breakdown, fractures.

3. Fatigue as a result of high intensity exercise: – Depletion of high energy phosphates within muscle; – Decrease in intracellular pH; – Lactic acid accumulation. Fatigue in response to sub-maximal exercise: – Depletion of muscular fuel stores; – Hyperthermia & dehydration; – Electrolyte loss.