The Claim

If you want to get stronger at squats, doing squats is way better than doing leg extensions—but if you want to get stronger at leg extensions, both exercises work about the same.

Source: Comparison of Muscle Hypertrophy and Strength Adaptations Induced by Back Squat and Leg Extension Resistance Exercises

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
48score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

If you want to get stronger at squats, doing squats is way better than doing leg extensions—but if you want to get stronger at leg extensions, both exercises work about the same.

See the scientific wording

Back squat training leads to greater improvements in back squat 3RM strength (+46.7%) compared to leg extension training (+21.3%) in untrained young women after 8 weeks, while both exercises produce similar gains in leg extension 3RM strength (+19.8% vs. +23.4%), suggesting strength gains are more specific to the trained movement pattern.

What the research says

1 study
  1. Study: Comparison of Muscle Hypertrophy and Strength Adaptations Induced by Back Squat and Leg Extension Resistance Exercises

    People who did squats got much stronger at squats, but not necessarily at leg extensions. People who did leg extensions got stronger at leg extensions, but not much stronger at squats — so your body gets strong in the exact way you train.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.