Just working out by itself can make you stronger—like lifting things gets easier—but it won’t make your muscles or body bulk up more if you’re losing muscle due to old age or serious illness.
Claim Language
Language Strength
definitive
Uses definitive language (causes, prevents, cures)
The claim uses 'increases' and 'does not significantly increase', which are definitive verbs indicating direct causal effects with a quantified magnitude (0.89 effect size) and a clear absence of effect (no significant increase).
Context Details
Domain
exercise_science
Population
human
Subject
Exercise alone
Action
increases
Target
muscle strength by 0.89 effect size
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)
Can conditions of skeletal muscle loss be improved by combining exercise with anabolic–androgenic steroids? A systematic review and meta-analysis of testosterone-based interventions
The study found that just working out makes muscles stronger by a lot (0.89 effect size) but doesn’t make the body’s lean muscle mass go up much in people with muscle-wasting diseases — which is exactly what the claim says.