Different Weights, Different Muscle Gains
Higher- and lower-load resistance exercise training induce load-specific local muscle endurance changes in young women: a randomised trial.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Two groups of women trained their arms and legs with heavy and light weights, each side doing a different weight. After 10 weeks, their muscles got stronger and could do more reps—but which weight helped more depended on which kind of rep they tested.
Surprising Findings
Only low-load training increased arm muscle mass — high-load training did not.
Common fitness wisdom says heavy lifting is required for muscle growth. This study shows light weights (30–50% 1RM) were the only ones that increased arm muscle mass in untrained women.
Practical Takeaways
If you want to build arm muscle as a beginner, try light weights (30–50% 1RM) trained to failure — you may see growth without heavy loads.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Two groups of women trained their arms and legs with heavy and light weights, each side doing a different weight. After 10 weeks, their muscles got stronger and could do more reps—but which weight helped more depended on which kind of rep they tested.
Surprising Findings
Only low-load training increased arm muscle mass — high-load training did not.
Common fitness wisdom says heavy lifting is required for muscle growth. This study shows light weights (30–50% 1RM) were the only ones that increased arm muscle mass in untrained women.
Practical Takeaways
If you want to build arm muscle as a beginner, try light weights (30–50% 1RM) trained to failure — you may see growth without heavy loads.
Publication
Journal
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme
Year
2022
Authors
Matthew D Fliss, J. Stevenson, Sobhan Mardan-Dezfouli, Donna C W Li, C. Mitchell
Related Content
Claims (6)
When lifting weights with your arms, whether you use heavy or light weights, you get about the same improvement in how many reps you can do with both heavy and light weights.
Using light weights for arm exercises can make your arms slightly more muscular, but using light or heavy weights for leg exercises doesn’t change leg muscle size in young women who haven’t trained before.
Lifting heavy weights makes your legs much stronger than lifting light weights, but for your arms, both heavy and light weights make you about equally stronger.
If you lift heavy weights, you get better at doing more reps with heavy weights; if you lift light weights, you get better at doing more reps with light weights — your muscles adapt specifically to the weight you use.
Working out with weights three times a week for 10 weeks makes you better at doing more reps — but how much better depends on whether you used heavy or light weights.