The Claim
When strength is tested using a neutral device (neither free-weight nor machine-specific), free-weight training and machine-based training are associated with similar strength gains, with an effect size of 0.128 and a 95% confidence interval ranging from -0.303 to 0.559, indicating that general strength adaptations are comparable when testing is not modality-specific.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
If you measure strength with a tool that doesn’t favor free weights or machines, both kinds of workouts—free weights and machines—help you get just as strong. The difference between them is so small it might just be due to chance.
See the scientific wording
When strength is tested using a neutral device (neither free-weight nor machine-specific), free-weight and machine-based training are associated with similar strength gains (effect size: 0.128; 95% CI: -0.303, 0.559), suggesting that general strength adaptations are comparable when testing is not modality-specific.
What the research says
1 studyWhen you test strength with a device that’s not a machine or free weights, people who trained with machines and those who trained with free weights got equally strong — so it doesn’t really matter which one you pick if you just want to get stronger in general.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.