Answer:
Both
Explanation:
Endurance deals with how long you can do something that puts a physical strain on your body and not necessarily how much strain at once. That being said both physical strength and emotional strength play a big role in this. Physical strength is needed to be able to exert yourself and accomplish the initial task in the first place. While emotional strength is also needed in order to not give up and persevere as long as possible. Without will power (emotional strength) you will give up as soon as you are given the opportunity.
