The Claim
Whether you train one leg or both legs at once for 12 weeks, your legs get just as big and strong overall — the way you do the exercise doesn’t change how much muscle you build or how strong you become in general.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Whether you train one leg or both legs at once for 12 weeks, your legs get just as big and strong overall — the way you do the exercise doesn’t change how much muscle you build or how strong you become in general.
See the scientific wording
Unilateral and bilateral knee extension training produce equivalent increases in overall muscle thickness (quadriceps) and dynamic strength (1RM) in young women after 12 weeks, demonstrating that training modality does not influence muscle growth or general strength gains in this population.
What the research says
1 studyStudy: Neuromuscular Adaptations to Unilateral vs. Bilateral Strength Training in Women
Both one-legged and two-legged leg exercises made women’s thighs equally thicker and their overall leg strength equally stronger after 12 weeks, so it doesn’t matter which one you pick if your goal is general muscle growth and strength.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.