The Study
Effects of resistance training on hypertrophy, strength and tensiomyography parameters of elbow flexors: role of eccentric phase duration
This study is like a fair race between two groups of people who lifted weights differently — one group lifted slowly, one fast. It shows that slow lifting made people stronger, but didn't make their muscles bigger than fast lifting. We can say one method probably led to better strength, but we can't say it's the only way or that it works for everyone.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Two groups lifted weights with different speeds on the way down — one fast, one slow — but both lifted until they couldn't do another rep.
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 568 / 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.
- 1Slowing down the lowering phase makes you significantly stronger without making your muscles bigger — useful if you want to lift heavier weights, not just bigger arms.
- 2Both groups got about 15–18% bigger biceps.
- 3The slow-lowering group got 23.5% stronger; the fast-lowering group got 11.6% stronger.
- 4Muscle stiffness (Dm) went down equally in both.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Biology of Sport
Year
2021
Authors
Filip Kojić, Igor Ranisavljev, D. Ćosić, D. Popović, S. Stojiljković, V. Ilic
Related Content
Claims (7)
When the total amount of weight lifted is the same, changing how slowly you lower the weight during resistance training does not change how much muscle grows.
In people who have not trained before, lifting weights with a 1-second or 4-second lowering phase results in the same amount of biceps muscle growth, around 15–18%.
In people who have not trained before, lifting weights with a 4-second lowering phase increases maximum strength more than using a 1-second lowering phase, even though both methods build the same amount of muscle, showing that slower lowering movements lead to greater improvements in nervous system control of muscle force.
Resistance training with slow or fast eccentric movements reduces radial deformation in the biceps brachii by 12–13%, which reflects increased muscle stiffness due to muscle growth, regardless of the speed of the lowering phase.
In people who have not trained before, doing resistance exercises twice a week for seven weeks at 60–70% of their maximum strength until muscle failure results in measurable increases in muscle size and strength, whether the lowering phase of the movement is slow or fast.
In untrained individuals, as the biceps muscle gets thicker, the radial deformation measured by tensiomyography decreases in a predictable way, suggesting this measurement can detect muscle growth without invasive procedures.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.