Research
Hormonal
Intramuscular factors, specifically changes in Androgen Receptor (AR) protein content and p70S6K phosphorylation, are significant predictors of muscle hypertrophy, explaining more variance than systemic hormones.
Muscle growth is driven by local signals within the muscle, such as Androgen Receptor content and p70S6K phosphorylation, rather than systemic hormone levels. Consistent resistance training upregulates these local factors, which are the true drivers of hypertrophy.
GoodSupportsHIGH confidence
Acute increases, in p70S6K phosphorylation and changes in muscle AR protein content correlated with muscle hypertrophy implicating intramuscular rather than systemic processes in mediating hypertrophy.
Why this rating
Prospective study with rigorous molecular analysis and regression modeling.
Source
Muscular and Systemic Correlates of Resistance Training-Induced Muscle Hypertrophy
Cameron J. Mitchell et al. · PLoS ONE · 2013
DOI 10.1371/journal.pone.0078636
cohort · n=23Cited 183×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
- Acute post-exercise increases in systemic hormones (testosterone, GH, IGF-1) are not related to muscle hypertrophy following resistance training.Good
- The acute post-exercise increase in Interleukin-6 (IL-6) is correlated with muscle hypertrophy, but it does not add predictive value beyond local muscle factors like AR and p70S6K.Good
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