The Study
The effect of myofibril and sarcoplasmic hypertrophy training on muscle hypertrophy and strength
This study shows that one type of weight training (heavy lifting) was linked to bigger muscles and more strength than another type (lighter, high-rep lifting) in a small group of young men. We can’t say for sure that the training caused the difference because the study wasn’t clear on whether people or testers knew who was doing which workout.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Two groups of young men did different workouts for 8 weeks: one lifted heavy weights with few reps, the other lifted lighter weights with many reps. Scientists measured their muscles and strength before and after.
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 559 / 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, the results suggest that if you want more visible muscle growth and strength, lifting heavy may be better than light weights with many reps.
- 2The heavy-weight group gained more muscle in chest and back.
- 3Both groups got stronger, but heavy weights worked better for big lifts like bench and squat.
- 4Muscle scans showed growth, but arms and waist didn’t get noticeably bigger.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Sport Sciences for Health
Year
2025
Authors
Haci Tunahan Gezer, H. Sözen, Ali Aslan, Hilal Altaş, Olgu Küçan
Related Content
Claims (3)
If young guys lift heavy weights with fewer reps, they’ll likely build more chest and back muscle than if they lift lighter weights with more reps — at least over 8 weeks.
The changes in muscle size caused by different workout routines may be too small to measure accurately with current tools, making it impossible to tell which routine is truly more effective.
If young guys lift weights for eight weeks—whether they go heavy or do more reps—they’ll likely build muscle in their upper body and back, and that can be seen with ultrasound scans.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.