Exercise and Regulation of Protein Metabolism.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing mechanistic and physiological literature without systematic review methodology.
PubMed 26477911 · doi:10.1016/bs.pmbts.2015.06.015
What was done
This narrative review synthesized literature on skeletal muscle protein turnover, detailing the use of stable isotopically labeled amino acid tracers to evaluate muscle protein synthesis (MPS) and muscle protein breakdown (MPB) in response to exercise, nutritional protein intake, and underlying molecular signaling pathways.
What was found
The abstract reports no numerical data, sample sizes, or effect estimates. It summarizes that exercise stimulates both MPS and MPB, while dietary protein intake potentiates MPS and attenuates MPB. The molecular response involves mRNA translation pathways (e.g., mechanistic target of rapamycin) alongside degradation pathways (autophagy and ubiquitin-proteasome), though the exact mechanisms explaining distinct adaptations between resistance and endurance exercise remain incompletely defined.
Why it matters
It provides a conceptual overview of the tracer methods and intracellular signaling pathways that coordinate skeletal muscle remodeling and proteostasis in response to mechanical loading and feeding.
Limits
The paper is a non-systematic narrative review with no defined search protocol, study selection criteria, or quantitative data synthesis. The abstract provides no primary human data, population demographics, or quantitative metrics.
Cited by
- supports Muscle protein synthesis increases after both endurance-type exercise and resistance-type exercise.