If young men eat much less and exercise a lot for four weeks while taking a high dose of testosterone, they gain a few extra kilograms of muscle compared to those taking a fake pill—even though their strength and leg function don’t get better.
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. The phrase 'despite no improvement' further reinforces a definitive contrast between outcomes, suggesting the effect is observed as a factual result under the described conditions.
Context Details
Domain
exercise_science
Population
human
Subject
Healthy young men (18–39 years)
Action
increases
Target
lean body mass by 2.5 to 3.8 kg compared to placebo, despite no improvement in muscle strength or lower-limb function
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)
The study gave young men a high dose of testosterone while they were eating much less and exercising a lot, and found they kept more muscle than those who got a fake shot—even though they didn’t get stronger. This matches the claim perfectly.