Endurance is the preservation of energy so Power and Agility is sustained for the duration of the marathon. 

Stamina is often equated with heart and lung capacity - aerobic capacity - the capacity of the heart and lungs to supply the muscles with enough oxygen and nutrients, and remove enough waste products to keep on going.  Cardiovascular fatigue robs you of power.

Another form of fatigue is neurological.  It can be central or in the neurological attachment to the muscle.  When you are neurologically fatigued, you lose coordination.  The muscles won't fire correctly.  The type of movement you are capable of becomes more and more crude until you are impaired.  Neuromuscular fatigue wipes out your agility, your coordination and control. You become more prone to errors, accidents and injury.

Use Posture Control Insoles(TM) to preserve energy by encouraging more linear and optimal body mechanics.   It starts with your foundation - your feet.