Doing leg presses and leg extensions for 12 weeks both make your main thigh muscles bigger about the same amount, but leg presses also make your butt and inner thigh muscles grow more, while leg extensions make the front part of your thigh (rectus femoris) grow much more.

31

Pro

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Against

Evidence from Studies

Supporting (1)

31

Community contributions welcome

31

Hypertrophic Effects of Single- versus Multi-Joint Exercise: A Direct Comparison Between Knee Extension and Leg Press.

Randomized Controlled Trial

Human

2026 Feb 5

The study found that leg press and knee extension both made the front thigh muscles bigger about the same amount, but leg press also made your butt and inner thigh muscles grow more, while knee extension made one specific thigh muscle (rectus femoris) grow much more — just like the claim said.

Contradicting (0)

0

Community contributions welcome

No contradicting evidence found

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

Hypertrophic Effects of Single- versus Multi-Joint Exercise: A Direct Comparison Between Knee Extension and Leg Press.

Score: 31

DOI: 10.1249/MSS.0000000000003957

Similar Assertions

Doing leg presses and leg extensions for 12 weeks both make your main thigh muscles bigger in about the same way, but only leg extensions make the front part of your thigh (rectus femoris) grow significantly.

31

0

90%

If you want to make the front part of your thigh (rectus femoris) bigger, leg extensions work better than leg presses — after 12 weeks, leg extensions made it grow 12% more than leg presses did.

31

0

87%

Leg presses make your butt and inner thigh muscles bigger, but leg extensions don’t — if you want to grow those muscles, leg presses are the better choice.

31

0

86%

If you’re already experienced with weightlifting and train your legs twice a week for 8 weeks with hard sets, your muscles will grow whether you take short breaks between reps or not.

45

0

82%

Doing leg extensions makes the front thigh muscle bigger along its whole length more than doing squats, especially near the knee.

48

0

82%