The Study
Physiological Differences Between Low Versus High Skeletal Muscle Hypertrophic Responders to Resistance Exercise Training: Current Perspectives and Future Research Directions
This study is like a teacher summarizing what other scientists have found about why some people get bigger muscles from lifting weights and others don’t. It says 'maybe this, maybe that'—but it didn’t do any experiments itself, so it can’t say for sure what causes the difference.
Analysis score
Maximum 5 for a narrative review.
Where the score came from
Some people’s muscles grow a lot when they lift weights, while others barely change—even when they do the same workout.
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 51 / 100
Quality score
Based on clinical experience or non-systematic literature reviews. The lowest level of evidence as they are most susceptible to bias and personal perspective.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—83% muscle growth is huge for a human; 4% is almost nothing, meaning two people could have wildly different results from the same training.
- 2High responders: muscles grew up to 83% bigger; ribosomes increased up to 32%.
- 3Low responders: muscles grew 4% or less.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Physiology
Year
2018
Authors
M. Roberts, Cody T Haun, C. Mobley, Petey W. Mumford, M. Romero, Paul A. Roberson, C. Vann, J. McCarthy
Related Content
Claims (7)
Some people’s muscles grow way more than others when they lift weights, and this might be because their muscle cells make more of the tiny machines (ribosomes) that help build muscle protein.
Some people’s genes might make them build a little more muscle from weight training than others, but these specific genes don’t explain much of why some people get way stronger than others.
People who get much stronger from weight training tend to make more of the cellular machinery (ribosomes) that helps build muscle, while those who don’t get as strong show little to no change in this machinery.
Some people get much stronger and build more muscle from weight training than others—this might be because their muscle cells grow more new nuclei, but not every study agrees on this.
Some people who lift weights and end up with more of a certain protein in their muscles tend to grow bigger muscles, but not everyone sees this link—some people with lots of the protein don’t grow much, and others with less do.
Some people get much bigger and stronger from weight training than others—even when they do the exact same workouts—because everyone’s body responds differently to exercise.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.