The Claim
Circulating levels of free testosterone, growth hormone (GH), and insulin-like growth factor 1 (IGF-1) following acute resistance exercise are not associated with muscle hypertrophy after 16 weeks of training in young men, challenging the hypothesis that systemic anabolic hormones drive individual variability in muscle growth.
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 working out with weights, the levels of certain hormones in the blood don’t predict whether a guy will gain more or less muscle over 16 weeks — so those hormones probably aren’t the main reason some people grow bigger muscles than others.
See the scientific wording
Circulating levels of free testosterone, growth hormone (GH), and insulin-like growth factor 1 (IGF-1) following acute resistance exercise are not associated with muscle hypertrophy after 16 weeks of training in young men, challenging the hypothesis that systemic anabolic hormones drive individual variability in muscle growth.
What the research says
1 studyStudy: Muscular and Systemic Correlates of Resistance Training-Induced Muscle Hypertrophy
The study found no significant correlations between acute post-exercise AUC of testosterone, GH, or IGF-1 and hypertrophy (all p > 0.05), even after training. This directly contradicts popular assumptions and supports the study’s central thesis that systemic hormones are not primary drivers of hypertrophy variability.
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.