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Muscles May Preserve a Shortcut To Restore Lost Strength (npr.org)

New research reviewed in the journal Frontiers in Physiology suggests that muscle nuclei -- the factories that power new muscle growth -- could give older muscles an edge in regaining fitness later on. "Muscles need to be versatile to meet animals' needs to move," reports NPR. "Muscle cells can be sculpted into many forms and can stretch to volumes 100,000 times larger than a normal cell. Muscle cells gain this flexibility by breaking the biological norm of one nucleus to a cell; some muscle cells house thousands of nuclei. In mammals, these extra nuclei come from stem cells called satellite cells that surround the muscle. When demands on the muscle increase, these satellite cells fuse with muscle cells, combining their nuclei and paving the way for more muscle." From the report: Physiologists had thought that a single nucleus supported a certain volume of cell. As a muscle cell grew, it needed more nuclei to support that extra volume. But as a muscle shrinks from lack of use, it gets rid of those unnecessary extra nuclei. This view found support in studies that found nuclei were scrapped as muscles atrophied. But [Kristian Gundersen, a muscle biologist from the University of Oslo] and [Lawrence Schwartz, a biologist at the University of Massachusetts] say those experiments overlooked what was really happening.

Take a cross section of muscle tissue and you'll find a sort of marbled mishmash of muscle cells surrounded by numerous other cell types, such as satellite cells and fibroblasts. Researchers could have been measuring the death of cells that support muscle and incorrectly inferred that muscle cells lose their nuclei, according to Gundersen and Schwartz. Gundersen and colleagues developed another method that zoomed in on individual muscle cells. The researchers injected a stain into muscle cells that mice use to flex their toes. The stain spreads throughout the muscle cells, illuminating their nuclei. Gundersen could then track the nuclei over time as he induced muscle growth by giving the mice testosterone, a steroid hormone. Later, after stopping the testosterone, he could watch what happened as those muscles atrophied. Unsurprisingly, testosterone boosted nuclei number. But those extra nuclei stuck around, even as the muscle shrank by half.
Gundersen thinks the results contradict the dogma that nuclei disappear when muscles atrophy. "Nuclei are lost by cell death," he says, "just not the actual muscle nuclei that confer strength." What's more, he says these retained extra nuclei might explain how a muscle remembers its past fitness.

42 comments

  1. Story from 2010 by js290 · · Score: 1

    No More Gym? Don't Worry, Your Muscles Remember https://www.npr.org/templates/...

    --
    "Tempers are wearing thin. Let's just hope some robot doesn't kill everybody." --Bender
    1. Re: Story from 2010 by Anonymous Coward · · Score: 0

      No more gym?! You really want out of society that bad? What are you going to do? Sit in the living room and have a staring contest with your television?

    2. Re: Story from 2010 by Anonymous Coward · · Score: 0

      So much for my fierce workouts. I am sick of my muscles being torn apart on a daily basis. And my trainer was a really cruel bastard ran around me in circles. I told him to get the fuck out.

  2. I couldn't insure my calves by Anonymous Coward · · Score: 1

    Which is a crying shame

    1. Re:I couldn't insure my calves by mrbester · · Score: 1

      Never mind, I 'm sure they were delicious.

      --
      "Wait. Something's happening. It's opening up! My God, it's full of apricots!"
  3. Rain Is Wet by Anonymous Coward · · Score: 0

    "Muscles need to be versatile to meet animals' needs to move," reports NPR.

    You heard it here first on Slashdot, readers.

    1. Re: Rain Is Wet by Anonymous Coward · · Score: 0

      I wasnt aware of these facts. Very disturbing and I may need to rethink my regimen /s

  4. Muscle memory by ubungy · · Score: 5, Insightful

    A physiological theory for something that's been observed and widely believed true, that it's easier to regain lost muscle size/strength than to develop the same for the first time. I wonder over what timeframe this effect could be observed, months, years? Interestingly, this is also an argument against transgender athletes, who were born male but transition to female, competing in female competition. Even though you may be on hormone therapy to get a few markers within a certain range, your training history as a male still provides an unfair advantage as muscle satellite cells will still contribute to strength and hypertrophy even with varying hormone levels.

    1. Re:Muscle memory by Vegan+Cyclist · · Score: 5, Interesting

      In my own experience as a fairly high-level bike racer, it's about 2yrs before a serious decline.. In 2014 I moved cities, the new one was a lot less bike-friendly, and I went from training/racing 4-5 days a week to barely commuting. When I did get on the bike for the first year or so, it wasn't too bad, and seemed like there was a fair bit of 'muscle memory'. After that things were a lot less comfortable when I got in the saddle. In 2017 I moved back to my home city, and started training/racing, and after a year I was reasonably fit, but still nowhere near my peak. Even 1.5yrs later I'm still working pretty hard to regain that fitness. (Age is probably also a factor, at 42 this year.)

      As for the discussion about transgender athletes, I have wondered about this, and haven't seen much discussion on this particular area. There is a similar argument about athletes who cheat/dope, and how long those benefits last....being able to train harder does convey better fitness, and even when 'going clean' I think there's still a lot of residual benefits from the doped training. I do wonder if there's a similar occurrence in gender going from male to female.

      On the flip side, is this even a question for female athletes who switch to male?

      And please don't vote this down - I think we should be able to have a discussion on the matter, and I've been friends with and supportive of trans athletes since at least 2006 and am fully supportive of their inclusion in sport in whatever capacity those athletes wish to compete in. That doesn't mean we can't also ask hard and uncomfortable questions and try and come up with sporting competition that's more fair for all...in many sports (especially at lower levels) the gender split is unnecessary even, and 'ability based' competition is a growing trend, where you race people who are at a similar level, regardless of age or gender.

    2. Re:Muscle memory by Anonymous Coward · · Score: 1

      I have also wondered about the effects of aging on the reconditioning process. As a younger person I could slack off for an extended period and recover my fitness level in a fairly brief if somewhat painful bout of training. As I have aged (and added various prescription medicines) I cannot return to the old levels, it takes longer, and conditioning seems to disappear much more rapidly. It's not anywhere near cost effective to spend the time daily on conditioning to maintain a subpar level and suffer the increased risk of injury too.

    3. Re:Muscle memory by Deaddy · · Score: 5, Informative

      Anecdotal evidence shows that people, who used anabolic stereoids in the past, will still benefit from them, although clearly to a lesser extent. The same is true for male-to-female-transgenders. Research on this topic is however quite difficult, as no ethics board will allow you to shoot realistic dosings of testosterone in people, who are also willing to lay them off later.

      As to your personal experience, bike racing is actually a pretty catabolic sport, i.e. high level cyclists show very little muscle, in particular outside of the legs. Consequently muscle memory is pretty irrelevant, if not hindering, and other factors should determine how fast you get back on track. One thing might be that with declining testosterone (just a shot in the dark) the ability to innervate your muscles goes down, so you are less efficient in terms of force production per muscle mass.

      Finally, I am quite happy to see some more evidence for the nuclei-theory of muscle memory. It is long enough around to even be featured in textbooks, but we are still not sufficiently sure about it.

    4. Re:Muscle memory by Anonymous Coward · · Score: 0

      As a former competitive bodybuilder who was also involved in strength sports, it was always pretty much known that once someone took steroids to break through previous plateaus or to get stronger/bigger quicker before even hitting that brick wall, they always had an advantage even after stopping the use of drugs. This is a point I try to get through to kids in the gym becoming obsessed with size/strength and considering steroids and all the other drugs. Once you juice, you can never go back. You will always have juiced and any accomplishments from then on will have been influenced by those drugs unlike a clean athlete (I am not anti-drug, BTW - people should be allowed to make their own choices in that matter).

      As for the transgender topic, doping a guy up on female hormones won't make him fair competition with women. Different but related with lots of data points, the amount of drugs a typical woman has to take just to reach the strength and size of an average guy not taking drugs who doesn't even workout much should illustrate that point. The elite women taking absurd amounts of drugs typically won't even be competitive with high end drug free male athletes. I don't think I have ever seen a women anywhere in the country press more weight than I used to (I remained drug free - not an easy choice) and I'm just a has been that never even was - dime a dozen even though always considered a beast by normal people.

      I really can't even begin to fathom the suggestion that a transgender women (man becoming a women) would be allowed to compete against female athletes.

    5. Re:Muscle memory by Vegan+Cyclist · · Score: 1

      Yeah, it's a pretty tricky topic, but I think we need to keep looking at it.

      Totally agree about cycling in general, it's mainly what your aerobic engine is capable of. In my own case, I do tend to focus on much shorter events that are more anaerobic, on the velodrome. I'm not a pure sprinter, but my aerobic ability is still taking its time to return, and a lot of that has to do with blood flow, oxygen uptake in muscles, how many kj those muscles can burn, etc.. And it was still a stark contrast from the first year to the fourth.

      That's the fun thing with science as we understand these systems more and more - long-held suspicions are confirmed. =)

    6. Re:Muscle memory by MrKaos · · Score: 1

      >And please don't vote this down - I think we should be able to have a discussion on the matter, and I've been friends with and supportive of trans athletes since at least 2006 and am fully supportive of their inclusion in sport in whatever capacity those athletes wish to compete in.

      Bodies accumulate scarring in the muscles has been my experience of training Martial Arts. After 30+ years training I took some time off to do extensive dry needling physiotherapy for almost 4 years. Nothing like a thin flexy needle in a dirty knot in my back, legs or anywhere else.

      It is an intense process and when the scarred up tissue releases, first it completely exhausts you with relief and then you're just more loose and limber as you gradually re-balance the tension between your limbs to a more relaxed configuration.

      My experiences with how the body can heal itself we extraordinary, 33 injuries were uncovered. The releases of larger injuries put me into shock twice and required several days rest before I could move.

      So far I've only been able to do light training however everything feels smooth and fast, I can't wait to be able to do leg work however that is something that is still being worked on. Only skipping or swimming, no squats or dead-lifts, etc.

      I know that this is mainly my will power to not be a grumpy from accumulated injury so I'll be passing this onto the people treating me and ask them and see what they have to say.

      --
      My ism, it's full of beliefs.
    7. Re: Muscle memory by Anonymous Coward · · Score: 0

      Dude, in your case I fear it may have to do with your diet. :-P

  5. Re: A shortcut to lost strength? by Anonymous Coward · · Score: 0

    He never had the muscle mass to regain.

  6. Re: "science" by Anonymous Coward · · Score: 0

    Nice work of fiction written by delusional nut case controling narsicists thinking some imaginary figure talked to them. They should have been locked up or beheaded for being crazy lunatics. But they lived in a gullible day where the wool was easily pulled over the majority of the population. They have done nothing but harm society and bring down the human race.

  7. Re: A shortcut to lost strength? by Anonymous Coward · · Score: 0

    Classic /. Comment completely irrelevant kudos

  8. As expected by Anonymous Coward · · Score: 1

    As a trainer, ive always thought similarly. Once you get into good shape, it changes you permanently. You get fat differently, you retain your 'build' so to speak. Now, this is something I felt was true, but had only anecdotal evidence for. Interesting to see that our simple observations on fitness can turn out correct.

  9. Re: "science" by Anonymous Coward · · Score: 0

    You sound like the usual liberal secularist ANTIFA terrorist, SJW politicaly correct, gun grabbing, video game hating loser. Why should anyone listen to you when they can have the absolute truth of the word of the Lord instead? Do you think the power of the word hasn't defeated losers like you in the past? Do you think your lies are any match?

  10. Re:"science" by Anonymous Coward · · Score: 0

    Oh no! I can't tell if this is a parody or not. Things have gotten that bad that there are people out there who would deliver the content of that post in all seriousness with a straight face. Please, stop the world, I want to get off.

  11. Re: "science" by Anonymous Coward · · Score: 0

    More of a threat go ahead bury your head in the sand you parody of a human and no worries we are hardly likely to confuse you with such a paragon of virtue as Pelosi

  12. Grandpa will mess you up... by atouk · · Score: 3, Interesting

    So science has just discovered "Old Man Strength." Never mess with a retired iron worker, machinist, miner or anyone else that did physical labor their entire life. This is known.

  13. Re: "science" by Anonymous Coward · · Score: 0

    I've seen a child say: "Harry Potter is true! Any time you try to prove me wrong, you're just making up lies!"

    You know what though? Just a gullible child. Adults should grow out of this phase.

  14. Re: the color orange by Anonymous Coward · · Score: 0

    Maybe he should start with his size 75 waist? Hard to trust a fat man.

  15. Fits with my subjective experience. by Anonymous Coward · · Score: 0

    I've always found after a period without exercise regaining muscle up to the point I'd previously reached very fast and easy. What's slow is going beyond that point.

  16. Re: "science" by Anonymous Coward · · Score: 0

    Well, Harry Potter is quite real. Made a woman very rich. Meanwhile you struggle to make ends meet, always fearing that your job will be automated, outsourced or sent overseas. You know, there is a way out and it can be painless.

  17. Strengh is a neuromuscular characteristic by Anonymous Coward · · Score: 1

    The summary (and maybe TFA, who reads it?) is mixing two very different things. The idea of "fitness" is usually related to muscle size. That seems to be what the research is about.
    Strength, OTOH, is neuromuscular. It depends on both the physiologic state of the muscle (how big it is being one aspect), but also, and mostly, on the nervous system.
    That's why weightlifters keep increasing their strength for years without gaining weight; (Ex)athletes regain strength quickly; That is also why they can easily get injured when they come back to training (their nervous system sends contractions that their muscle can't handle).

    1. Re: Strengh is a neuromuscular characteristic by Anonymous Coward · · Score: 0

      Just had that happen. I was a deadlifting fool up until about six years ago; restarted a training routine and felt like I was comfortably and quickly returning to my old numbers until my forearms felt like they were on fire after a given workout. Everything else in the posterior chain felt fine. Six months later the forearms are finally healed up and Iâ(TM)m cautiously getting back into it, albeit more slowly.

  18. Re: "science" by Anonymous Coward · · Score: 0

    I was going to say the same thing about the SJWs!

  19. past fitness by Anonymous Coward · · Score: 0

    In my experience past fitness levels give you edge over very long spans of time, certainly any length without much exercise I went through until now. Even after well over 10 years going back to gym produces startlingly rapid progress, especially considering age difference.
    Same for running, going back to it after 5 or 10 years it takes a short time, few months, to converge to the same km splits.
    Disclaimer - we're talking about an amateur sportsman here, but there's no reason why it should be completely different for pros.