Useful Reference Works
Horse Sense: 2. How Does a Horse Travel?
In rough country, a rider must match his horse's ability, strength, and agility with the terrain. Going uphill, an experienced trail horse will generally slow down, having to propel both his weight and his rider's upwards. Going downhill... well, surely you saw the Man From Snowy River! Unlike in the movies, horses cannot go like blazes, indefinitely. Yes, they can go farther faster than two-legged folk, but just like you and me, they do need to catch their breath, they need to rest, they need to cool down and get a good drink of water. Three days of hard riding and poor care will knock visible pounds off a horse. A week of that, and he won't even look like the same animal. Good husbandry is the secret to keeping a horse in shape for a long, productive life.