The molecular athlete: exercise physiology from mechanisms to medals
Physiological Reviews synthesis of muscle plasticity from inactive to elite, including aging athletes
Scope (abstract)
Skeletal muscle shows remarkable plasticity to contractile loading; capacity spans a continuum from inactive individuals with low endurance and strength to elite athletes whose performances rest on pleiotropic training-induced adaptations
The authors state that understanding of how muscle integrates, interprets and coordinates these signals is incomplete — so elite training methods still rely largely on "trial and error", with coaches' and athletes' practice often providing the basis for "post hoc" scientific enquiry
Synopsis of the morphological and functional changes and the molecular mechanisms of adaptation to endurance- and resistance-based training
The review frames these traits against inborn genetic and between-person differences in exercise capacity, paying particular attention to aging athletes
Key Findings (themes)
Endurance vs resistance adaptation — distinct morphological/functional outcomes with partly shared molecular machinery (abstract)
Genetics and interindividual differences in capacity and trainability (abstract)
Aging athletes as an explicit focus (abstract)
PGC-1α convergence — Ca²⁺ signalling (calcineurin/CaMK → CREB/ATF2) and energy-stress signalling (AMPK) both converge on PGC-1α → mitochondrial biogenesis (full text, checked 2026-09-27; the paper does not assign these branches to low vs high intensity)
Omics integration (transcriptomics, proteomics, metabolomics) to map the adaptation network (full text, checked 2026-09-27)
Practical Application
Narrative review (Furrer, Hawley & Handschin 2023): muscle plasticity spans a continuum from inactive to elite; the molecular understanding of how training signals are integrated is still incomplete, so elite training remains largely "trial and error" with science following practice; the review synthesizes the mechanisms of endurance and resistance adaptation in the context of genetic differences and aging athletes. Meaning: mechanism papers explain why training works, they do not yet prescribe it — protocol choices should rest on training trials, not on signalling diagrams.
Varying the stimulus engages partly distinct pathways — a rationale (inference) for mixed-intensity periodization, not a tested prescription
Reference for the masters-athlete discussion: the review gives aging athletes special consideration
Limitations
Narrative review, no systematic method; heavy mechanism focus — less protocol-level prescription
Rodent and cell models underlie many findings
Rapidly evolving field
How this entry was checked and changed
Why this level
regraded 2026-09-27 from A: authoritative narrative review from a leading group, no systematic method
Content correction 2026-09-27
Level A -> B+ (narrative review from a leading group).
Scope rewritten to the abstract (continuum from inactive to elite, understanding "incomplete", trial-and-error training, genetic differences, aging athletes); PGC-1α convergence and omics kept but marked full text.
Added Tier/Sport lines and an abstract-based lead.
Lines labelled "full text; not checked" were read against the open-access full text (PMC10110736): 1 confirmed and relabelled; 1 corrected to what the paper says.