In stiff-leg deadlifts, the size of the biceps femoris muscle (back of the thigh) seems to matter more for getting stronger at other exercises—unlike the other hamstring muscles.

Pro

Against

Evidence from Studies

Supporting (1)

Community contributions welcome

Minimal Role of Hamstring Hypertrophy in Strength Transfer Between Nordic Hamstring and Stiff-Leg Deadlift: A Blinded Randomized Controlled Trial

Randomized Controlled Trial

Human

Contradicting (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

Minimal Role of Hamstring Hypertrophy in Strength Transfer Between Nordic Hamstring and Stiff-Leg Deadlift: A Blinded Randomized Controlled Trial

Score: 82

DOI: 10.1101/2024.12.17.24319207

Similar Assertions

Even when your hamstrings get bigger from training, that doesn’t really predict how much stronger you’ll get at the other exercise—so bigger muscles don’t mean much more strength in this case.

80%

If you're a guy who lifts weights, doing kickbacks might work your back thigh muscle way more than the leg press — like 76% more, according to one study.

72%