The Claim
Changes in agonist neural drive, quadriceps muscle volume, and pre-training strength collectively account for approximately 60% of the variance in individual strength gains following 12 weeks of isometric knee extensor resistance training in healthy young men, with agonist neural drive being the strongest single predictor among these factors.
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 healthy young men who perform 12 weeks of isometric knee extension training, about 60% of the differences in how much stronger they become can be explained by changes in nerve signals to the muscle, increases in muscle size, and how strong they were before training. The change in nerve signals explains more of this variation than the other factors.
See the scientific wording
Changes in agonist neural drive, quadriceps muscle volume, and pre-training strength together explain approximately 60% of the variation in individual strength gains after 12 weeks of isometric knee extensor resistance training in healthy young men, with neural drive being the strongest single predictor.
When you train your thigh muscles by pushing against resistance, your brain gets better at sending stronger signals to make those muscles contract harder. At the same time, the muscle fibers themselves get bigger from increased protein building and new cell additions. The bigger muscles can produce more force, and the improved brain signals make more of those fibers fire at the same time. How strong you were before training also matters because it sets the baseline for how much room there is to improve. Together, these changes—better brain signals, bigger muscles, and starting strength—explain most of why some people get much stronger than others after training.
What the research says
1 studyAfter 12 weeks of leg strength training, the study found that how much stronger someone gets depends mostly on how much their brain gets better at telling their thigh muscles to work harder, plus how much their muscles grow and how strong they were before starting—these three things explain about 60% of why people improve differently.
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.