The Study
Effects of Low- vs. High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men
This study is like a fair test where men were randomly picked to do different workouts. It shows that both heavy and light weight training can build muscle, but heavy weights are better for getting stronger. We can't be sure these results would be the same for women or older people.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Lifting heavy weights makes you stronger, lifting light weights many times makes you last longer, but both build muscle the same if you push until you can't lift anymore.
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 546 / 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, differences are meaningful for training; heavy weights improve strength more, light weights improve endurance more.
- 2Heavy weights: 19.6% stronger in legs, light weights: 16.6% more endurance in arms.
- 3Muscle growth: heavy 5.3-9.3%, light 5.2-9.5%.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Strength and Conditioning Research
Year
2015
Authors
B. Schoenfeld, M. Peterson, Daniel I. Ogborn, B. Contreras, G. T. Sonmez
Related Content
Videos (2)
Claims (7)
When people lift weights until they can no longer complete another repetition, the amount of muscle growth is similar whether they use light, moderate, or heavy weights.
When resistance training is performed until muscle fatigue is reached, lifting light weights and lifting heavy weights result in the same amount of muscle growth.
Lifting heavier weights for fewer reps makes well-trained young men stronger faster than lifting lighter weights for more reps, especially in exercises like squats and bench presses.
Lifting lighter weights many times in a row helps well-trained young men do more push-ups longer than lifting heavier weights fewer times, after 8 weeks of training.
Lifting heavier weights for fewer reps makes your legs much stronger than lifting lighter weights for more reps, but both types of training help your upper body a little bit too, and this might work differently for different muscles.
For young men who are already fit and lift weights until they can't anymore, doing lots of lighter reps builds muscle just as well as doing fewer heavy reps over 8 weeks.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.