The Role of Mammalian Target of Rapamycin (mTOR) and Adenosine Monophosphate-Activated Protein Kinase (AMPK) Signaling in Skeletal Muscle Hypertrophy: A Literature Review With Implications for Health and Disease.
Level 5 - mechanism / opinion, no new human data
Narrative literature review summarizing mechanistic pathways and secondary literature without systematic methodology.
PubMed 41356921 · doi:10.7759/cureus.96018
What was done
This was a narrative literature review evaluating the interaction between mammalian target of rapamycin (mTOR) and adenosine monophosphate-activated protein kinase (AMPK) signaling in skeletal muscle hypertrophy, metabolic health, and aging, alongside practical exercise and nutritional strategies.
What was found
The abstract reports that for resistance-trained individuals, a total protein intake of approximately 1.6 g/kg/day maximizes muscle protein synthesis, with diminishing returns above this intake. Per-meal protein distributions of approximately 0.25 g/kg in younger adults and 0.40 g/kg in older adults enhance anabolic efficiency. Rapidly absorbed, leucine-rich protein sources (e.g., whey) provide the strongest mTOR activation. It also notes that concurrent endurance training can attenuate hypertrophy depending on session timing and intensity, while time-restricted feeding preserves body composition if energy and protein needs are fulfilled.
Why it matters
It translates molecular signaling dynamics into actionable nutrition and training recommendations, emphasizing that long-term metabolic health and muscle maintenance require a balance between anabolic stimulation and catabolic renewal rather than continuous mTOR activation.
Limits
As a narrative review, it lacks systematic search criteria, explicit inclusion/exclusion protocols, and formal risk-of-bias assessments. The abstract presents generalized recommendations aggregated from past literature rather than new primary empirical data.
Cited by
- supports mTOR activation is the primary mechanistic pathway responsible for skeletal muscle hypertrophy from resistance training.