What are the homeopathic medicines used to increase stamina and endurance?

Stamina, endurance. Activity directed exercise is the best way to increase stamina and endurance.
Treat the cause. Before prescribing a homeopathic remedy, one has to understand what the patient is suffering & how s/he is experiencing it. You don't just give something to increase endurance -- you need to know what the problem is first. Is there fatigue? What is it like? What are the specific concerns, and how intense? Is the patient pharmaceuticals which are producing weakness, etc? All are important.