Why you get stronger when you lift weights
Muscle Growth Is Very Strongly Correlated with Strength Gains after Lower Body Resistance Training: New Insight from Within-Participant Associations
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Neuromuscular activation (nerve firing) only explained ~13% of strength gains, despite being the most commonly cited reason for early strength improvements.
For decades, coaches and textbooks taught that beginners get stronger ‘because their nervous system adapts’—but this study shows that even in beginners, muscle growth dominates.
Practical Takeaways
Focus on progressive overload and exercises that build muscle mass (like squats, leg presses) rather than just practicing technique or lifting lighter with perfect form.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Neuromuscular activation (nerve firing) only explained ~13% of strength gains, despite being the most commonly cited reason for early strength improvements.
For decades, coaches and textbooks taught that beginners get stronger ‘because their nervous system adapts’—but this study shows that even in beginners, muscle growth dominates.
Practical Takeaways
Focus on progressive overload and exercises that build muscle mass (like squats, leg presses) rather than just practicing technique or lifting lighter with perfect form.
Publication
Journal
Medicine and Science in Sports and Exercise
Year
2025
Authors
Elisa A Marques, T. G. Balshaw, M. Funnell, Emmet J. McDermott, S. Maeo, Lewis J. James, Jonathan P Folland
Related Content
Claims (6)
Individual hypertrophic responses to resistance training are highly variable across muscle groups and are not consistently correlated between upper and lower body musculature.
After 15 weeks of leg workouts, the men’s quadriceps muscles grew by about 13%, measured precisely with MRI scans.
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.
When young men who had never lifted weights before trained their legs for 15 weeks, the more their leg muscles grew, the stronger they got—this link was extremely strong.
When these men got stronger, their muscle signals (measured by EMG) also got stronger—but not as strongly as their muscles grew.