Combat endurance

Combat endurance is the time that a military system or unit can remain in combat before having to withdraw due to depleted resources. The definition is not precise; for example the combat endurance of an aircraft, without qualification, is usually the time the aircraft can remain at an altitude suitable for combat, but in a particular theatre of operations it is the time it can remain in the area of combat. During the Battle of Britain, for example, the combat endurance of German fighters was the time they could remain over Britain, i.e., their inherent (endurance)less the time to travel from their base to Britain, and the time to return—about 15 minutes.

In addition to fuel the expenditure of ammunition and other consumables will reduce combat endurance, for example the limiting factors for an nuclear attack submarine are its torpedoes or for an nuclear aircraft carrier aviation fuel and aircraft munitions.

Military units will have a combat endurance, how long they can stay in the field for, measured by how long its logistics train can keep its component subunits supplied with food, fuel, ammunition and spare parts etc.

The United States Department of Defense and NATO define endurance as "the time an aircraft can continue flying, or a ground vehicle or ship can continue operating, under specified conditions, e.g., without refueling."

Combat endurance training is also used for a system of physical training associated with stamina.