When scientists looked at what made these men stronger, muscle growth explained over five times more of the improvement than changes in how their nerves activated their muscles.
Scientific Claim
In previously untrained young men, muscle growth accounts for more than five times the contribution to strength gains compared to changes in neuromuscular activation, as shown by standardized beta coefficients of 0.88–0.94 versus 0.13–0.17 in linear mixed models.
Original Statement
“Linear mixed models revealed muscle growth and changes in neuromuscular activation both had significant positive effects on strength gain, but muscle growth contributed >5-fold more than neuromuscular activation (standardized beta coefficient = 0.88–0.94 vs 0.13–017).”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The claim uses 'accounts for' in a statistical context (beta coefficients), which is appropriate for association in regression models. No causal language is used, and the values are accurately reported.
Evidence from Studies
Supporting (1)
The study found that when untrained guys get stronger from lifting weights, most of the gain comes from their muscles getting bigger—not from their nerves getting better at telling muscles to work. Muscle growth was more than five times more important than nerve changes.