Stamina and agility can be acquired by a good exercise and stretching program. Agility comes from stretching and bending. Plan your camp, make your reservations, buy and mix your food, study maps, layout each day's ride, and read everything you can find about the area. The easiest, and often the best, trail riding involves making one camp and planning daily rides from that camp. Breaking and setting up camp consume energy that is more fun to spend riding.
Food needs to be planned in advance for items that cook as quickly as possible.
If feasible, use foods that can be mixed or cooked before leaving home. Save your time and energy for enjoying nature and your horse. Choose trail recipes that use dried ingredients like powdered milk. Mix these ingredients ahead of time, in the proper number of servings, and store them in a zip-lock plastic bag. On the trail, add water, then mix in the bag.