The Claim
Twelve weeks of resistance training does not significantly alter fascicle length in the vastus lateralis muscle of individuals with stage-3 chronic kidney disease, irrespective of training frequency, and muscle growth in this population is driven by increases in cross-sectional area and pennation angle rather than fiber elongation.
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.
After 12 weeks of strength training, the muscle fibers in the thigh of people with stage-3 chronic kidney disease do not become longer. Instead, the muscles grow thicker due to changes in fiber arrangement and cross-sectional size.
See the scientific wording
Resistance training for 12 weeks does not significantly change fascicle length in the vastus lateralis muscle of individuals with stage-3 chronic kidney disease, regardless of training frequency, suggesting that muscle growth in this population occurs primarily through increases in cross-sectional area and pennation angle rather than fiber elongation.
When muscles are loaded during resistance training, muscle fibers respond by adding new contractile units side by side instead than end to end. This makes each fiber thicker and causes the fibers to angle more sharply relative to the tendon. The muscle becomes larger in width and more angled, but the individual fibers do not grow longer. This change allows the muscle to produce more force without changing the length of its fibers.
What the research says
1 studyIn people with moderate kidney disease, doing leg exercises for 12 weeks made their thigh muscles thicker and more angled, but didn’t make the individual muscle fibers longer — which is exactly what the claim says.
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.