Question

How could an increase in mitochondria-rich cells increase energy in a mouse?

Answer 1

This is pretty simple: mitochondria are the powerhouse of the cell, so as soon as you add more, there is more energy.

Answer 2

From birth, the mouse's muscle cells made more mitochondria and burned more fat than the muscle cells of normal mice would. Additional research on mice showed that a drug known as AICAR had the same influence as endurance training.