Question

How are red muscle fibres specialized for sustained work over a prolonged period while a white muscle fibre suffers from fatigue after a shorter work?

Answer 1

Since red muscle fibers have much better capillary supply and a greater number of mitochondrion which is responsible for ATP supply to the muscle cell, therefore they are specialized for sustained work. On the other hand, white muscle cells have less capillary, fewer mitochondria, so they do not have such good supply as the red cells. White cells have lots of glycogen stored, which is quickly accessible and they can produce more force when the need arises, but when that glycogen is depleted you feel muscle tiredness and it takes much longer time for the muscle to recover.