The Claim

If you're a guy new to lifting and want your front thigh muscle to grow as much as possible, doing leg extensions with your hip more bent (40°) is probably better than keeping it straighter (90°).

Source: The effects of hip flexion angle on quadriceps femoris muscle hypertrophy in the leg extension exercise

What the research says

Supports is higher

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

Supports
54score
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're a guy new to lifting and want your front thigh muscle to grow as much as possible, doing leg extensions with your hip more bent (40°) is probably better than keeping it straighter (90°).

See the scientific wording

For untrained men aiming to maximize rectus femoris growth, training the leg extension exercise with reduced hip flexion (40°) is a more effective strategy than 90° hip flexion.

What the research says

1 study

  1. Study: The effects of hip flexion angle on quadriceps femoris muscle hypertrophy in the leg extension exercise

    The study found that bending the hip only 40 degrees during leg extensions made the front thigh muscle (rectus femoris) grow more than bending it 90 degrees — so if you want to build that muscle faster, use a less bent hip position.

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.