Article: Science: Is exercise actually good for the brain?

"There are plenty of reasons to get off your duff and exercise—but is improving your brain one of them? The U.S. Centers for Disease Control and Prevention touts exercise as a way to “boost brain health,” while the World Health Organization suggests that about 2 hours of moderate activity or 75 minutes of vigorous activity per week can help improve thinking and memory skills.

But new research reveals a more complex picture. One recent review of the literature suggests the studies tying exercise to brain health may have important limitations, including small sample sizes. Other studies suggest there is no one-size-fits-all approach to exercising as a way to boost cognition or prevent age-related cognitive decline. Still others indicate exercise may actually be harmful in people with certain medical conditions. Here’s the latest on what we know."

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"Sanabria Lucena and colleagues recently conducted an “umbrella review,” analyzing 24 existing meta-analyses, which in turn encompassed 109 randomized controlled trials linking exercise to cognition in healthy people. Most of these reported a positive effect. But the review, published in Nature Human Behaviour in March, found that many of the original studies had limitations, including small numbers of participants.

Another issue, the researchers say, is that the control groups in different studies had widely varying levels of physical activity. The discrepancy has led to inconsistent findings about the size of the effect exercise has on cognition. The field also likely suffers from a bias toward publishing positive results, the authors note. And they found that the meta-analyses had limitations of their own, such as a failure to include all relevant published studies."

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"Can exercise be harmful in some groups?
Some studies link exercise to worse cognitive outcomes in people who have or are predisposed to certain medical conditions. For example, Pamela Shaw, a psychologist at the University of Sheffield, and her team examined studies published between 2009 and 2021 on the relationship between exercise and the neurodegenerative condition amyotrophic lateral sclerosis (ALS). Their analysis, published last month in the journal Brain, showed that vigorous exercise was linked with higher risk of ALS.

A 2021 study looked at the roughly 10% of patients with ALS who have a mutation in a gene called C9ORF72, the most common genetic risk factor for ALS. In this group, higher rates of exercise were associated with an earlier onset of the disease. The reasons aren’t clear, Shaw says, but for some people already at genetic risk of ALS, strenuous physical activity may “tip the disease into manifesting itself.

In encephalomyelitis/chronic fatigue syndrome, exercise is thought to potentially worsen symptoms, and an early trial supporting exercise as a treatment generated controversy in the field. Similarly, some physicians initially recommended exercise for patients with Long Covid, but studies have revealed that physical activity can lead to more fatigue and worsen respiratory symptoms."

https://www.science.org/content/article/exercise-actually-good-brain

 

Great that our society’s current fetishisation of exercise is being challenged.

I am willing to consider the possibility that, all other things being equal, exercise can be a good thing, but it should always have been obvious that for some exercise is counter indicated or should only be approached with caution.

 

It seems intuitive to me that the right amount will be good, and too much will be bad. The right amount will vary between individuals. Yet the current approach is typically to define an exercise amount target that is the same for everyone.

And there seems to be little interest in determining the factors that limit the amount of exercise tolerated or the factors that make exercise pleasant versus unpleasant.

 

This is the second time we've seen this in a week. What is going on?

 

I guess the myalgia got better.

 

my body disagrees.

 

Healthcare providers too often forget that recovery is what makes exercise beneficial. Exercise is only one part of the process, namely the stimulus, and there cannot be physiological improvement, be it an increase in cardiovascular fitness or strength or muscle growth, without adequate recovery.

Perhaps more of them would come to this realization if they looked at high level sports, where athletes and their teams do everything they can to enhance recovery.

 

Good to see this sort of material out there. The exercise lobby is so strong despite no evidence of benefit for weight loss or other outcomes.

 

An early trial? What? It was THE definitive trial after dozens had been held over nearly 2 decades and the controversial claims were made before a single trial happened. It was very expensive, too. How is that an early trial?! I guess by the standards of serious research but this is still the largest trial related to ME/CFS. What a weird framing.

Also if it's just an early trial, why is it essentially held like they're scrolls handed down from the heavens that must be followed lest ye be smitten by lightning?

Early trial, my ass.

 

It's more profound than that, though. Using muscles tears them and they rebuild stronger, longer. There is probably a lot going on here that relates to how the immune system rebuilds after damage. And exercise is damage, it's just that there is normally a natural process that takes advantage of it and seems to be broken with us.

 

Can't speak to the science, but I do know that when I was able to exercise to a significant extent, it improved my sleep and thinking ability. Obviously, trying that now has different results.