The Study
Fasted‐state skeletal muscle protein synthesis after resistance exercise is altered with training
This study is like taking pictures of 8 people's muscles before and after exercise. It shows what changed, but it can't prove the exercise caused the changes because there was no proper comparison group and the group was very small.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Lifting weights makes muscles grow by changing how proteins are made after exercise.
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 533 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, shows training adapts how muscles respond to exercise for efficient growth.
- 2Resting protein mix up 48%, muscle fibers grew bigger, exercise boosted muscle protein 42-44% in both trained and untrained legs.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of Physiology
Year
2005
Authors
P. L. Kim, R. Staron, Stuart M Phillips
Related Content
Claims (6)
When you start lifting weights, your muscles build new protein faster in the first week than they do after 10 weeks, even if you keep training.
When young men who haven't trained before do one-arm exercises for eight weeks, their resting muscle building speed goes up by almost half in that arm, but the part that builds muscle fibers stays the same, showing different parts of muscle react differently to exercise.
When young men who don't normally exercise do eight weeks of weight training, their fast-twitch muscle fibers get bigger, but their slow-twitch fibers stay the same size and the overall mix of muscle types doesn't change.
When you do strength training, your body gets better at building the proteins that make muscles strong, while cutting back on making other less important proteins. It's like your body learns to focus on what really matters for muscle power.
Lifting weights at a challenging level makes your muscles build more protein, and this boost happens just as much in arms or legs that are used to exercising as in ones that aren't.
When people lift weights at a high effort level, their untrained muscles build more protein quickly, but their already-trained muscles don't get the same boost, even if they do more work.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.