The Claim

Isometric training at long muscle lengths and full range of motion isotonic training produce similar overall quadriceps femoris hypertrophy in resistance-trained individuals, with no meaningful difference in summed anterior thigh muscle thickness between the two methods.

Source: The Effects of Long Muscle Length Isometric versus Full Range of Motion Isotonic Training on Regional Quadriceps Femoris Hypertrophy in Resistance-Trained Individuals.

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.

Description
1 study reviewed
In plain English

If you train your quads using either holding a static position with your legs stretched out or doing full squat-like movements, both ways build your thigh muscles about the same amount — neither one is better than the other.

See the scientific wording

Isometric training at long muscle lengths and full range of motion isotonic training produce similar overall quadriceps femoris hypertrophy in resistance-trained individuals, with no meaningful difference in summed anterior thigh muscle thickness between the two methods.

Why this might work

When muscles are stretched and held under tension, the fibers experience strong physical stress that triggers the building of new muscle proteins, leading to thicker muscle fibers. This happens whether the muscle is pushed to its full length while holding still or while moving through a full range of motion.

Supported mechanismbased on 1 study

What the research says

1 study
  1. Study: The Effects of Long Muscle Length Isometric versus Full Range of Motion Isotonic Training on Regional Quadriceps Femoris Hypertrophy in Resistance-Trained Individuals.

    Both holding your leg straight out and doing full squats built your thigh muscles about the same amount—neither way was clearly better than the other.

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.