People who build some muscle with more training (but not a lot) show reduced activity in systems that break down muscle and increased activity in systems that help move proteins around and respond to hormones.
Scientific Claim
Medium responders to resistance training show downregulation of muscle breakdown pathways (proteasome and spliceosome) and upregulation of hormone-related and membrane trafficking pathways, which may support muscle growth under moderate training volume.
Original Statement
“Hypertrophy in medium responders was marked by downregulation of pathways linked with muscle catabolism (proteasome and spliceosome), modulations on distinct RT-related metabolic response, and biological processes associated with hormone- and steroid-related pathways.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The study reports correlations between molecular changes and phenotypes, not experimental control of pathways. 'Marked by' implies association, which is appropriate.
More Accurate Statement
“Medium responders to resistance training are associated with downregulation of proteasome and spliceosome pathways and upregulation of hormone-related and membrane trafficking pathways.”
Evidence from Studies
Supporting (1)
Molecular signatures underlying heterogenous hypertrophy responsiveness to resistance training in older men and women: a within-subject design.
In people who gain muscle with moderate exercise but not with light exercise, their bodies turn down the systems that break down muscle and turn up systems that help build and move proteins around—helping muscles grow.