Regular, aerobic exercise is essential to a horse's physical and mental health.
Aerobic exercise improves cardiovascular and muscle fitness, helps control weight, and supports overall immune function.
Exercise also has positive behavioral effects. Studies have found that aerobic exercise releases endorphins, natural neurotransmitter chemicals that produce a feeling of happiness and well-being.
Regular aerobic exercise also reduces stress and anxiety disorders. A large, 2015 Finnish study of dogs found that "the largest environmental factor associating with noise sensitivity and separation anxiety was the amount of daily exercise".