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Muscle Memory Discovery Ends “Use It or Lose It” Dogma

New research shows that extra nuclei gained during exercise persist even after a muscle shrinks from disuse, disease or ageing – and can be mobilised rapidly to facilitate bigger gains on retraining.

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The old adage “use it or lose it” tells us: if you stop using your muscles, they’ll shrink. Until recently, scientists thought this meant that nuclei – the cell control centers that build and maintain muscle fibers – are also lost to sloth.

But according to a review published in Frontiers in Physiology, modern lab techniques now allow us to see that nuclei gained during training persist even when muscle cells shrink due to disuse or start to break down. These residual ‘myonuclei’ allow more and faster growth when muscles are retrained – suggesting that we can “bank” muscle growth potential in our teens to prevent frailty in old age. It also suggests that athletes who cheat and grow their muscles with steroids may go undetected.

Our biggest cells are in our muscles, and they’re all fused together

Syncytium. Sounds like a neo-noir comic book series. It’s actually a special type of tissue in your body, where cells are fused together extra close – so close, that they behave a like a giant single cell.

“Heart, bone and even placenta are built on these networks of cells,” says Lawrence Schwartz, Professor of Biology at the University of Massachusetts. “But by far our biggest cells – and biggest syncytia – are our muscles.”

Like the Sin City series, it appeared at first that everything was black and white with syncytia.

“Muscle growth...

The full text of this article can be purchased from Informit.