The Claim

In resistance-trained individuals, lengthened partial range-of-motion training produces muscle hypertrophy in the arms and thighs that is equivalent to the hypertrophy produced by full range-of-motion training, provided that total volume and effort are equated.

Source: Training BEYOND Failure - This NEW Study is Epic

What the research says

Supports is higher

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

Supports
71score
Challenges
45score

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
4 studies reviewed
In plain English

Doing only the bottom part of an exercise (where the muscle is stretched) can build as much muscle in your arms and legs as doing the full movement, as long as you put in the same amount of effort and work.

See the scientific wording

In trained individuals, lengthened partial range-of-motion training results in equivalent arm and thigh muscle hypertrophy compared to full range of motion training when volume and effort are equated.

Why this might work

When muscles are stretched under load, the fibers and surrounding structures pull tightly, sending a signal that tells the muscle to build more protein. This happens whether the movement is short or full, as long as the muscle stays stretched and the effort is high. The added protein makes the muscle fibers thicker, leading to growth that matches what you get from full movements.

Verified mechanismbased on 4 studies

What the research says

4 studies
  1. Study: The effects of lengthened-partial range of motion resistance training of the limbs on arm and thigh muscle cross-sectional area

    The study found that doing shorter lifts that focus on the stretched part of the muscle works about as well as full lifts for building arm and leg muscle in trained people, as long as effort and volume are the same.

  2. Study: Lengthened partial repetitions elicit similar muscular adaptations as full range of motion repetitions during resistance training in trained individuals

    The study found that doing partial reps that focus on the stretched part of the movement builds arm muscle just as well as full reps, as long as everything else is equal. This supports the idea that both ways work about the same.

  3. Study: Partial Range, Full Gains? The Effect of 8 Weeks of Partial Range of Motion Training at Long Muscle Lengths on Elbow Flexor Hypertrophy and Strength in Trained Individuals

    This study found that doing only the bottom part of a bicep curl built just as much arm muscle as doing the full curl, as long as the total work and effort were the same. So yes, you can get similar muscle growth with partial movements if you push just as hard.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 4 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.