The Study
Muscle Transcriptional Networks Linked to Resistance Exercise Training Hypertrophic Response Heterogeneity.
This study found that some people’s muscles had certain gene patterns before they started lifting weights, and those patterns were linked to whether they got bigger or not. But it doesn’t prove the genes made them grow — just that they were connected.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists studied how older adults' muscles grow after lifting weights and found that what their muscles were doing before training mattered more than what changed during training.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 551 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — knowing someone's baseline muscle gene activity could help predict if they’ll respond well to weight training, helping tailor exercise plans.
- 231 people trained for 14 weeks; muscle growth varied a lot.
- 3Their muscle gene activity before training predicted growth better than changes during training.
- 4One gene network linked to poor growth included mTOR and mitochondria genes.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Physiological genomics
Year
2021
Authors
K. Lavin, M. Bell, J. McAdam, Bailey D. Peck, R. G. Walton, S. Windham, S. Tuggle, D. Long, P. Kern, C. Peterson, M. Bamman
Related Content
Claims (8)
When people gain muscle from resistance training, the amount of growth varies between muscles, and these differences are partly linked to how similar the responses are across muscles, but much of the variation comes from personal biological traits unrelated to the workout itself.
If you're new to lifting weights, how muscular you already are doesn't really predict how much you'll grow from training — it's not a strong clue.
Even if your muscles don’t get much bigger from lifting weights, your body still improves how it uses energy, like making your muscles better at burning fuel efficiently.
People’s muscles before they start lifting weights already have different gene activity patterns, and those patterns seem to predict how much their muscles will grow after training.
Some people’s muscles have a hidden gene pattern before training that’s linked to poor growth — it involves genes that control energy production, muscle structure, and how cells respond to signals.
Very few gene patterns actually changed in sync with muscle growth — most of the important signals were already there before training even started.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.