Why some guys get bigger muscles faster than others
Muscular and Systemic Correlates of Resistance Training-Induced Muscle Hypertrophy
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Even when everyone does the same workouts and eats the same food, some people grow bigger muscles than others. This study found it’s not because of hormone spikes after exercise, but because of what happens inside the muscle itself.
Surprising Findings
Muscle growth varied from -7% to +80% among people doing the exact same program.
Everyone assumed identical training = similar results. This shows genetics or cellular biology can make you lose muscle while others gain massively.
Practical Takeaways
Focus on progressive overload and recovery—not hormone-boosting supplements. Your muscle’s internal response is what counts.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Even when everyone does the same workouts and eats the same food, some people grow bigger muscles than others. This study found it’s not because of hormone spikes after exercise, but because of what happens inside the muscle itself.
Surprising Findings
Muscle growth varied from -7% to +80% among people doing the exact same program.
Everyone assumed identical training = similar results. This shows genetics or cellular biology can make you lose muscle while others gain massively.
Practical Takeaways
Focus on progressive overload and recovery—not hormone-boosting supplements. Your muscle’s internal response is what counts.
Publication
Journal
PLoS ONE
Year
2013
Authors
C. Mitchell, T. Churchward-Venne, Leeann M. Bellamy, G. Parise, S. Baker, Stuart M Phillips
Related Content
Claims (6)
Even if your testosterone, growth hormone, or IGF-1 levels spike right after a workout, you don’t need those spikes to grow muscle — your muscles can still get bigger without them.
When young guys who’ve never lifted before train with weights for 4 months, those whose muscles produce more of a specific protein (called androgen receptor) tend to grow bigger muscles—even if they all do the same workouts and eat the same food.
In guys who are new to weightlifting, how strongly their muscles signal growth right after a workout (at the 5-hour mark) seems to predict how much muscle they’ll gain over the next 4 months.
In guys who are new to weightlifting, a spike in a certain body chemical (IL-6) right after a workout is linked to bigger muscles after 16 weeks of training—but that spike alone doesn’t fully explain why some guys get bigger than others, because other internal changes in the muscle also matter.
Even if your testosterone, growth hormone, and IGF-1 levels spike after a workout, that doesn’t mean you’ll grow more muscle over time—those hormone spikes don’t seem to explain why some guys get bigger than others after 16 weeks of lifting weights.