Muscles remember past glory

Extra nuclei produced by training survive disuse

Pumping up is easier for people who have been buff before, and now scientists think they know why — muscles retain a memory of their former fitness even as they wither from lack of use.

MUSCULAR MEMORIES Muscles hold memories of their former fitness in nuclei (green, shown on muscle fiber) that help the muscle bounce back to fitness when training begins after a period of inactivity.