You can build muscle by working one arm or leg at a time, even if your body doesn’t show higher levels of muscle-building hormones in your blood—so maybe it’s the physical stress on the muscle itself, not the hormones, that makes it grow.
Claim Language
Language Strength
probability
Uses probability language (may, likely, can)
The claim uses 'may be sufficient'—a probabilistic phrase indicating possibility rather than certainty—along with 'suggesting' which implies inference without definitive proof, placing it in the probability category.
Context Details
Domain
exercise_science
Population
human
Subject
Muscle hypertrophy from unilateral resistance training
Action
occurs without detectable elevations in systemic anabolic hormones, suggesting that local mechanisms may be sufficient to drive
Target
muscle growth
Intervention Details
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.
Evidence from Studies
Supporting (1)
This study showed that lifting weights with just one leg made that leg’s muscles grow bigger—even though the body’s overall hormone levels didn’t go up. That means muscles can grow just from the workout itself, not because of hormones circulating in the blood.