The Claim

Long repetition duration during resistance exercise diminishes muscle hypertrophy in rats, as evidenced by reduced muscle mass and fiber cross-sectional area compared to short and medium durations, despite matched torque-time integrals, indicating that contraction speed independently influences muscle growth.

Source: Effects of repetition duration on skeletal muscle hypertrophy in a rat model of resistance exercise.

What the research says

Supports is higher

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

Supports
12score
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 rats lift weights slowly for longer periods, they grow less muscle than if they lift quickly or at a medium pace—even if the total effort is the same—because how fast they move matters for muscle growth.

See the scientific wording

Long repetition duration during resistance exercise diminishes muscle hypertrophy in rats, as evidenced by reduced muscle mass and fiber cross-sectional area compared to short and medium durations, despite matched torque-time integrals, indicating that contraction speed independently influences muscle growth.

What the research says

1 study
  1. Study: Effects of repetition duration on skeletal muscle hypertrophy in a rat model of resistance exercise.

    In rats, doing resistance exercises slowly (9 seconds per rep) didn’t make muscles grow, even though the total effort was the same as faster reps. Quick reps (1 second) made muscles bigger, showing that how fast you do the exercise matters — not just how much total work you do.

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.

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