Second , endurance training speeds up the process of moving the lactate around the muscles and the body, a process that is called clearance.
Endurance training causes adaptations that speed up clearance.
When an athlete stresses the aerobic system, the body adapts in several ways. Oxygen can move more quickly to each muscle. Oxygen is necessary to produce the maximum amount of energy from pyruvate. Besides the availability of oxygen, there are other important factors which encourage the muscle to use pyruvate for fuel and speed up the use of lactate in adjacent muscles and the blood stream. Endurance training increases the density of mitochondria in certain cells.