The Claim
During 24 weeks of resistance training in frail elderly individuals, myonuclear domain size increases in both type I and type II muscle fibers regardless of protein supplementation, indicating that existing myonuclei support greater muscle fiber volume without addition of new nuclei.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
In frail older adults who perform resistance training for 24 weeks, the amount of muscle tissue each existing nucleus supports increases in both slow-twitch and fast-twitch muscle fibers, whether or not they take extra protein, and no new nuclei are added.
See the scientific wording
During 24 weeks of resistance training in frail elderly individuals, myonuclear domain size increases in both type I and type II muscle fibers regardless of protein supplementation, indicating that existing myonuclei support greater muscle fiber volume without addition of new nuclei.
When muscles are trained, the muscle fibers get bigger by adding more contractile proteins. Each nucleus in the muscle fiber can only manage a certain amount of muscle tissue, so as the fiber grows, each nucleus takes charge of a larger area. No new nuclei are added during this process; the existing ones simply handle more muscle volume.
What the research says
1 studyWhen frail older adults did strength training for 6 months, their muscle fibers got bigger, but the number of nuclei inside them didn’t increase — meaning each nucleus had to manage more muscle tissue, whether or not they drank protein shakes.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.