The Study
Effect of external load on muscle activation during the barbell back squat
This study shows what happens to muscle activity when women who lift weights do squats with different amounts of weight. It doesn’t prove that the weight causes the muscles to work harder, just that they tend to be more active when the load is heavier.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
This study looked at how hard different leg muscles work when strong women do back squats with different weights.
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 527 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, lifting heavier (80%-90% of max) makes leg muscles work harder, but going from 80% to 90% doesn't add much extra benefit.
- 2Muscles worked harder at 90% of max weight vs 40%-70%.
- 380% and 90% felt about the same.
- 4Glutes and hamstrings stayed balanced no matter the weight.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
European Journal of Sport Science
Year
2022
Authors
Sarah C. Martinez, John M. Coons, Kelton Mehls
Related Content
Claims (7)
When women who lift weights do squats with different levels of heavy weights, the way their thigh and butt muscles work together stays the same — no matter how heavy the weight is.
When women who lift weights do squats with a really heavy weight (close to their max), their leg and butt muscles have to work a lot harder than when they use lighter weights.
When women who lift weights do squats with 80% of their max weight, their butt muscles work way harder compared to their hamstrings — more than with lighter or heavier weights.
When women who lift weights do squats with a light weight (about 40% of their max), their butt and hamstring muscles work together in perfect balance as they lower down.
For women who lift weights regularly, squatting with 80% or 90% of your max weight activates your muscles about the same — going heavier doesn’t seem to turn on more muscle once you hit that range.
Your quads work hard during squats no matter how heavy the weight, but your glutes really kick in only when the weights are heavy or you're almost too tired to keep going.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.