The Study
Skeletal muscle and resistance exercise training; the role of protein synthesis in recovery and remodeling.
This study is like a teacher summarizing what other scientists have learned about how muscles grow when you lift weights. It doesn’t do any experiments itself, so it can’t say for sure that lifting weights causes bigger muscles—it just tells you what other studies have found.
Analysis score
Maximum 5 for a narrative review.
Where the score came from
When you lift weights, your muscles don't get bigger right away—they repair and rebuild during rest. Protein from food helps. At first, muscles swell and get busy making new machinery, but real growth takes weeks.
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—this explains why you don't see visible muscle growth right away, even if you're working out and eating protein.
- 2Muscle size doesn't increase measurably until 6–8 weeks of training, even though protein building starts immediately.
- 3High-intensity sprinting builds mitochondria but not bigger muscles in under 6 weeks.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of applied physiology
Year
2017
Authors
C. McGlory, M. Devries, Stuart M Phillips
Related Content
Claims (4)
Your muscles don't grow while you're lifting weights—they grow later, while you rest, because your body uses that time to repair and build new muscle tissue after the workout stresses them.
Doing short bursts of intense exercise can help your muscles make more proteins, especially the ones in energy factories inside cells, but it doesn’t always make your muscles bigger if you only do it for less than six weeks.
When you start lifting weights, your muscles might look bigger right away, but that’s just because they’re swollen and rearranging inside—not actually growing. Real muscle growth takes about 6 to 8 weeks to show up in measurements.
When you first start lifting weights, your muscles are mostly fixing tears from the workout—not growing bigger. After a few weeks, they switch from repair mode to growth mode.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.