Weightlifting is superior to other forms of exercise, an idea that is thoroughly at odds with mainstream and popular ideas about exercise.
Weightlifting enhances brain function, reverses sarcopenia, and lowers the death rate in cancer survivors. Garden-variety aerobic exercise had no effect on survival from cancer, while resistance training lowered death rates by one third; so in this one example, weight training is shown to be a vastly superior form of exercise.
Weightlifting is also superior in fighting aging.
Resistance training lowers levels of myostatin, one of the main ways muscle strength and mass are increased, since myostatin negatively regulates muscle strength and mass.
Myostatin increases with age, which partially accounts for loss of muscle mass and sarcopenia with aging. Mice that have been genetically engineered to have lower levels of myostatin live about 15% longer than wild-type mice. (See previous link.)
Therefore it follows that lowering myostatin through weightlifting should increase lifespan. (Branched chain amino acids, creatine, and polyphenols from chocolate and tea also lower myostatin.)
However, one thing has bothered me – and presumably a few others – about all this is the results of the now well-known parabiosis experiments on mice, in which young blood from young mice rejuvenated the brains and muscles of old mice. (See here and here.) The reason for the bit of bother is that the rejuvenating component of these experiments was said to be a protein, growth differentiation factor 11, or GDF11, which is “homologous”, that is, very similar, to myostatin.
We have, if not quite a paradox, then a confusion. GDF11, very similar to myostatin, allegedly rejuvenates young animals, while myostatin increases with aging.
What if there’s some kind of mistake here? It appears that there has been, since a new paper finds that GDF11 increases with age and is not the rejuvenating factor hitherto thought: GDF11 Increases with Age and Inhibits Skeletal Muscle Regeneration.
Age-related frailty may be due to decreased skeletal muscle regeneration. The role of TGF-β molecules myostatin and GDF11 in regeneration is unclear. Recent studies showed an age-related decrease in GDF11 and that GDF11 treatment improves muscle regeneration, which were contrary to prior studies. We now show that these recent claims are not reproducible and the reagents previously used to detect GDF11 are not GDF11 specific. We develop a GDF11-specific immunoassay and show a trend toward increased GDF11 levels in sera of aged rats and humans. GDF11 mRNA increases in rat muscle with age. Mechanistically, GDF11 and myostatin both induce SMAD2/3 phosphorylation, inhibit myoblast differentiation, and regulate identical downstream signaling. GDF11 significantly inhibited muscle regeneration and decreased satellite cell expansion in mice. Given early data in humans showing a trend for an age-related increase, GDF11 could be a target for pharmacologic blockade to treat age-related sarcopenia.
So, we get two important facts from this new study:
1. The previous study which implicated GDF11 in anti-aging processes was incorrect; GDF11 is a pro-aging molecule.
2. GDF11 and myostatin are indeed very similar and have similar effects, inhibiting muscle regeneration, decreasing satellite cell expansion, and increasing with age.
And we know that weightlifting decreases myostatin. Now someone should see whether weightlifting decreases GDF11. I would say it almost surely does.
Other forms of exercise can also decrease myostatin, but to my knowledge there are no direct comparisons of the efficacy of weightlifting versus aerobic or endurance exercise in doing so. However, we know that only weightlifting increases muscle mass, and therefore it follows that weightlifting must decrease myostatin levels more so than endurance training.
The case for weightlifting as an anti-aging intervention just got a lot stronger, in my opinion. The iron pill is good for what ails you, and if you are serious about lifespan extension or just your health in general, you should head over to your local gym and start lifting.