A brief review of critical processes in exercise-induced muscular hypertrophy.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing physiological mechanisms and nutritional studies without systematic review methodology.
PubMed 24791918 · doi:10.1007/s40279-014-0152-3
What was done
This narrative review synthesizes the physiological mechanisms governing exercise-induced skeletal muscle hypertrophy, focusing on the interplay between resistance exercise, postprandial hyperaminoacidemia, muscle protein synthesis (MPS), and muscle protein breakdown (MPB). It evaluates protein types, amino acid profiles (particularly leucine), co-ingested compounds, and energy-restricted contexts.
What was found
The abstract reports no numerical data. It notes that skeletal muscle hypertrophy requires positive muscle protein balance (MPS exceeding MPB) and satellite cell addition. Resistance exercise and postprandial hyperaminoacidemia act synergistically to raise MPS. Rapidly digested complete proteins rich in essential amino acids and leucine are identified as most effective. Adding carbohydrate, arginine, or glutamine to complete protein has not proven particularly effective for enhancing MPS or suppressing MPB. Higher protein intake combined with resistance training preserves or increases muscle mass during energy restriction.
Why it matters
It consolidates evidence on nutritional optimization for muscle growth, highlighting that complete, leucine-rich proteins are effective without the need for additional supplemental amino acids or carbohydrate additives.
Limits
As a narrative review, it lacks a systematic search protocol, risk-of-bias assessment, and quantitative effect sizes. The abstract does not report specific protein doses, participant demographics, or numerical outcomes.
Cited by
- supports Resistance exercise increases the rate of muscle protein breakdown as well as muscle protein synthesis.