If young men lift weights for 15 weeks, their biceps get significantly stronger—by about 20%—no matter if their body releases extra muscle-building hormones during the workout or not.
Claim Language
Language Strength
definitive
Uses definitive language (causes, prevents, cures)
The claim uses the verb 'increases' which implies a direct, certain cause-and-effect relationship, and 'no difference between conditions' which asserts a definitive absence of effect, both indicating definitive language.
Context Details
Domain
exercise_science
Population
human
Subject
young men
Action
increases
Target
isometric, 1-repetition maximum, and 10-repetition maximum strength in the elbow flexors
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 (0)
Contradicting (1)
Elevations in ostensibly anabolic hormones with resistance exercise enhance neither training-induced muscle hypertrophy nor strength of the elbow flexors.
The study found that lifting weights made young men’s arms stronger, no matter if their body released extra hormones or not — which matches part of the claim. But it didn’t measure exactly how much stronger they got, so we can’t confirm the 19–25% number.