The Claim
A 10-week resistance training program consisting of two weekly leg extension sessions induces measurable hypertrophy in the rectus femoris and vastus lateralis muscles of untrained young men, as quantified by ultrasound.
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.
Untrained young men who perform two leg extension sessions per week for 10 weeks experience measurable increases in the size of their rectus femoris and vastus lateralis muscles, as detected by ultrasound.
See the scientific wording
A 10-week resistance training program with two weekly leg extension sessions can induce measurable hypertrophy in the rectus femoris and vastus lateralis muscles of untrained young men, as quantified by ultrasound, confirming that this exercise is effective for quadriceps growth in beginners.
When someone does leg extensions with their hip slightly bent, the front thigh muscle gets stretched at the start of the movement. This stretch increases the force on the muscle fibers during the lift, which triggers chemical signals that tell the muscle to build more protein and add new muscle cells. Over time, this makes the muscle thicker and bigger.
What the research says
1 studyDoing leg extensions twice a week for 10 weeks made the front and outer thigh muscles bigger in guys who had never lifted before — no matter how they sat during the exercise. So yes, leg extensions work to build quad muscles for beginners.
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.