I don’t know if this article sheds some light on the paradox of why metformin has a detrimental effect on muscle growth with exercise, yet can also combat muscle loss due to sarcopenia or extended bed rest.
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Nir Barzilai, M.D. references another study (https://onlinelibrary.wiley.com/doi/full/10.1111/acel.13039) that aimed to discover how metformin affects muscle mass and strength in participants over 65. Half of the participants went on metformin, and half did not. After they engaged in resistance training, both groups had increased their muscle mass—but the metformin group experienced less muscle growth (likely due to metformin blunting the IGF-1 response, along with some other mechanisms like inhibiting mTORC1, a protein that regulates protein synthesis).
Again, you might consider this bad news. But Barzilai explains that the metformin group actually had the same amount of strength, despite having smaller muscles. “They did four tests for force—getting out of a chair and lifting—and it was the same,” he shares. “Every gram of muscle must have been stronger because they were doing just as well with and without metformin… So they had smaller muscles but better quality.”
For all of these reasons, Barzilai is leading a trial (the TAME trial) to show the FDA that this drug can prevent a cluster of age-related diseases in elderly people without diabetes.
“The combination drug metformin and galantamine (RJx-01) is under development for the treatment of sarcopenia, disuse-induced muscle atrophy and unspecified indications”
I’ve been taking metformin for about 15 years now. My gym sessions remain largely unchanged. I’m now 67 so unable to match what I could do when I was 35 but still OK. On a recent hot day I took out the garbage without a shirt and my neighbour (married man) commented loudly on my build (in a complimentary way). I was a bit embarrassed but also kind of pleased that the gym work has not been entirely in vain.
If you are interested in learning about the effects of metformin on people, I recommend you check out the presentation by Adam Konopka from last week. There are some significant negative effects on V02Max improvements, muscle recovery and also insulin sensitivity it seems.
Thank you. I read what you had posted earlier today. Yes; it seems that metformin interfered with the benefits of exercise in that study.
But I should say that (if I recall correctly) the patients took 1.7 g/day, which is a huge dose compared to my 500 Mg/day.
However, I’m willing to stop taking metformin on days that I run and see if my times for the set distance improve.
It’s not my job to “help you understand” or convince you of anything.
When I first started taking metformin, about 15 years ago, I did so on the basis of the available information and evidence. That obviously changes over time. My opinion and conclusions may change as new evidence becomes available.
However, if you look carefully at the presentation there are several still unresolved questions. There is also the big difference between the dose I take and the dose taken in the study. Many molecules, when ingested, induce a U-shaped response. Metformin may be one of them.
There are also unresolved nuances of exercise and it’s relation to longevity. If being “fit” is all that is needed to maximise longevity, then one might expect the ranks of centenarians to be replete with marathon runners. But I suspect they are, instead, filled with people from all walks of life.
At this stage of my life I am content with the strategy I have chosen since my early 50s. Metformin forms a small part of that, for better or worse.
I will continue to adapt my strategy as new information becomes available.
