Human exercise-mediated skeletal muscle hypertrophy is an intrinsic process.
Level 5 - mechanism / opinion, no new human data
Narrative review and mechanistic theoretical perspective without original trial data
PubMed 20541030 · doi:10.1016/j.biocel.2010.05.012
What was done
This paper provides a mechanistic review evaluating the determinants of resistance exercise-induced skeletal muscle hypertrophy in humans. It examines the physiological role of transient post-exercise elevations in systemic hormones (growth hormone, testosterone, IGF-1) versus local, muscle-intrinsic mechanical and intracellular signaling pathways (such as p70S6K, tension-sensing proteins, and membrane-derived factors).
What was found
The abstract reports no numerical data or statistical measures. Conceptually, it states that transient systemic hormone elevations following exercise do not determine acute muscle protein synthesis or hypertrophic outcomes. Instead, locally activated tension-sensing mechanisms and intrinsic signaling pathways directly stimulate muscle protein synthesis and myofibre protein accretion following mechanical loading.
Why it matters
This work challenges the widespread concept that post-exercise systemic hormonal spikes serve as proxy markers or primary drivers for muscle growth, highlighting local mechanical tension as the primary stimulus.
Limits
The abstract contains only narrative mechanism-based reasoning and presents no original empirical data, quantitative meta-analyses, or sample details. Direct interactions between baseline hormonal status and intrinsic mechanical pathways cannot be quantified from the text.
Cited by
- supports Acute, transient post-exercise elevations in systemic testosterone and growth hormone do not drive long-term muscle hypertrophy.