The Study
Myofiber hypertrophy adaptations following 6-weeks of low load resistance training with blood flow restriction in untrained males and females.
This is like a science experiment where people were randomly picked to try different exercises. It shows us that certain exercises probably cause muscle growth, but we can't be 100% sure because the researchers might have known which people did which exercises.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Lifting heavy weights makes muscles bigger, especially fast-twitch fibers. Light weights with restricted blood flow help men's muscles a little but not women's as much.
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 554 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, heavy training clearly builds muscle fibers; light training with blood flow restriction works moderately for men but minimally for women.
- 2Heavy training increased fast-twitch fibers by 11.6% in men and 24.3% in women.
- 3Light training with blood restriction had small effects (0.29-0.67 effect sizes).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of applied physiology
Year
2023
Authors
Tanner M. Reece, Joshua S Godwin, M. Strube, Anthony B. Ciccone, Kevan W. Stout, Jeremy R. Pearson, B. Vopat, P. Gallagher, M. Roberts, T. Herda
Related Content
Claims (5)
Lifting heavy weights three times a week for six weeks makes fast-twitch muscle fibers grow bigger by about 12% in people who don't usually exercise, showing it especially targets these powerful muscles.
Lifting heavy weights and doing lighter exercises with restricted blood flow both make your muscles grow bigger about the same amount, even though they work in slightly different ways inside the muscle.
Men naturally have bigger fast-twitch muscle fibers than women, even if neither exercise, showing a clear biological difference between sexes.
When men do light weightlifting with restricted blood flow, their muscles grow a decent amount, but women's muscles barely grow from the same workout, showing it works differently for each sex.
When scientists check muscle growth from exercise, taking tiny muscle samples doesn't match up well with other methods like ultrasound scans or strength tests, so using just the sample data isn't a great way to measure progress.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.