Muscles May Preserve a Shortcut To Restore Lost Strength (npr.org) 42
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.
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.
Story from 2010 (Score:1)
I couldn't insure my calves (Score:1)
Which is a crying shame
Re: (Score:1)
Never mind, I 'm sure they were delicious.
Muscle memory (Score:5, Insightful)
Re:Muscle memory (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.
Re: (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
Re:Muscle memory (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.
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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 fir
Re: (Score:2)
>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 r
As expected (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.
Grandpa will mess you up... (Score:3, Interesting)
Strengh is a neuromuscular characteristic (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