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There’s a good chance you’re familiar with something called motor learning — a.k.a. “motor memory” or, more commonly “muscle memory.” This is the thing that allows someone to ride a bike after many years away from the pedals, or tie their shoes after wearing sandals all summer. But while it’s super cool and convenient and good, the names for this phenomenon can also be a little misleading.

Because like, let’s be real: Muscles don’t store memories. They’re muscles, not brains. Except… here’s the weird part: Muscles can remember some things!

Just not in the way you’d think. This phenomenon has to do with muscle strength. Basically, if you work out, your muscles will kind of “remember” what it’s like to be strong.

So even if you take some time off from the gym, you’ll be able to bulk up faster when you return than if you had never started exercising. It sounds like it should be a fake life hack, but it’s legit! And it happens because of how muscles grow.

Whenever you increase the demand on your muscles — like by weight lifting, jogging, or or suddenly having to carry a 2 year old around all the time — you cause small tears in the tissue. These microtraumas release molecules that signal nearby satellite cells to swoop in and repair the damage. And during the repair, your muscle cells get thicker and stronger as new muscle fibers grow.

To help with all of this, some of the satellite cells even donate their nuclei to your muscle tissue. And that is a big deal. Nuclei in muscle cells are called myonuclei, and they’re responsible for telling your cells to make proteins.

So the more myonuclei you have, the faster you can create the protein you need to get stronger. This is awesome when you’re training, but here’s the best part: These nuclei stick around in your cells even when you lose muscle mass. So even if you take a break from exercising for a while, you’ll be able to recover more easily when you get back.

You’ll get stronger faster than the newbie over on the next treadmill. It’s possible that these benefits last for a long time, too. Studies in rats and insects have shown that, once muscle cells acquire myonuclei, they persist even after significant amounts of muscle atrophy.

So if this is also true in humans, it could mean that being fit earlier in life would carry over into old age. It would be easier for you to get stronger even during a time where muscle atrophy is common. And since muscle strength impacts things like bone health, that could have a huge impact on your quality of life.

So knowing this, I expect to see, out by the river in Missoula, Montana, just lots of SciShow employees and SciShow audience just lifting rocks, and puttin em down and lifting em again. It’s time! For us to be Rock Lifters!

Thanks for watching this episode of SciShow! If you want to learn more about how motor memory works, and why riding a bike is just like… well, riding a bike… you can check out our episode over on SciShow Psych. Did you know we have a psychology channel?

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