Lifting light or heavy weights can make muscles bigger the same way
Divergent Strength Gains but Similar Hypertrophy After Low-Load and High-Load Resistance Exercise Training in Trained Individuals: Many Roads Lead to Rome.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
People who lifted light weights with lots of reps and others who lifted heavy weights with few reps both got stronger and their muscles grew bigger — but only for big movements like squats, not small ones like bicep curls.
Surprising Findings
Low-load training led to a -3% decrease in single-joint strength, while high-load improved it by 9%—despite both being done to failure.
Common fitness advice says 'training to failure' makes load irrelevant—but here, load still mattered for small muscles.
Practical Takeaways
If you can’t lift heavy, use light weights with 20–25 reps to failure for squats, lunges, and deadlifts—you’ll still build strength and size.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
People who lifted light weights with lots of reps and others who lifted heavy weights with few reps both got stronger and their muscles grew bigger — but only for big movements like squats, not small ones like bicep curls.
Surprising Findings
Low-load training led to a -3% decrease in single-joint strength, while high-load improved it by 9%—despite both being done to failure.
Common fitness advice says 'training to failure' makes load irrelevant—but here, load still mattered for small muscles.
Practical Takeaways
If you can’t lift heavy, use light weights with 20–25 reps to failure for squats, lunges, and deadlifts—you’ll still build strength and size.
Publication
Journal
Journal of applied physiology
Year
2025
Authors
K. Cumming, Ingrid Cecelia Elvatun, Richard Kalenius, Gordan Divljak, T. Raastad, N. Psilander, Oscar Horwath
Related Content
Claims (6)
When resistance training is performed to volitional muscular failure, hypertrophic outcomes are equivalent across a wide range of loads (from low to high) and repetition ranges.
Even though muscles got bigger, the actual muscle fibers didn’t get thicker or change type—so the growth might be due to other factors like fluid or connective tissue.
Whether you lift light weights many times or heavy weights fewer times—both can make you stronger in exercises like squats and deadlifts, as long as you push to exhaustion.
For exercises that move just one joint—like bicep curls—lifting heavier weights leads to better strength gains than lifting lighter weights, even if both are done until exhaustion.
Whether you use light or heavy weights, your muscles can grow about the same amount if you train hard enough—both methods work for building muscle size.