Continuous Movement and Resting Places in the Open
The horse is in constant (24 hour) motion. Horses in the wild move around approximately 15 to 20 km per day to find food and water, and they have been doing this for millions of years. The horse's heart is relatively small compared to its body therefore, the horse needs to be in constant motion to move blood through its body (metabolic efficiency). The hooves are especially important because with each step, they pump blood back up the legs to the rest of the body. In doing so, they function in the same way an auxiliary heart pumps blood around the body.
A horse that is living in a stable and ridden for an hour a day only moves a few miles; this is far too little. When ridden in such a way, the horse is usually moved these few miles over a short period of the day, and not slowly and continuously over the entire day. In this case the heart is only supported by the pumping action of the muscles, joints and hooves for that hour per day, but for the rest of the time the circulatory system is functioning at a below-average level, therefore the heart has insufficient blood flow and becomes overstressed. This is one of the main causes for heart and circulatory problems in stabled horses.
Also with a lack of movement during a 24 hour period, there can be a loss of bone density and in foals this prevents the proper development of the entire organism, from lungs to hooves leading to conformation flaws.
The freedom of movement 24 hours a day is vital to the proper development, functioning and health of the entire horse form its circulatory system to its hooves.
Resting Places in the Open
A horse is a prey animal and does not hide in a cave with soft bedding. They only rest for short periods of time during the day and night, either standing with their heads hanging down or lying down for a short while. Resting time is also a time for defecation and urination.
Horses choose their resting places according to several criteria, with safety and survival being the most important. Firm ground and a clear view of the horses surroundings is important for a horse to feel safe.