Hormonal
Resistance exercise training in older adults preserves the capacity for myonuclear accretion (satellite cell fusion), indicating that the failure of aged muscle to hypertrophy is not caused by a lack of new nuclei or a myonuclear domain size ceiling.
If you are an older adult struggling to build muscle despite consistent resistance training, do not assume your muscle fibers have run out of capacity to grow. This research confirms that your muscles can still integrate new nuclei (via satellite cells) just as well as a younger person's. The bottleneck is likely not the structural capacity of the fiber, but rather the efficiency of protein synthesis machinery (ribosomes). Focus on high-intensity resistance training to maximize this preserved capacity.
Declines in myonuclei addition do not underlie impaired muscle growth capacity in older humans, supporting ribosomal and proteostasis impairments as we have previously reported.
Why this rating
Randomized controlled trial with human biopsies, though small sample size (n=10 per group).
Source
Neither myonuclear accretion nor a myonuclear domain size ceiling is a feature of the attenuated hypertrophic potential of aged human skeletal muscle
Matthew S. Brook et al. · GeroScience · 2022
DOI 10.1007/s11357-022-00651-y
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