Whether you have more 'slow-twitch' or 'fast-twitch' muscle fibers before training doesn’t seem to affect how much muscle you can build with lifting weights.

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Evidence from Studies

Supporting (1)

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Physiological Differences Between Low Versus High Skeletal Muscle Hypertrophic Responders to Resistance Exercise Training: Current Perspectives and Future Research Directions

Narrative Review

Animal

2018

The study looks at people who gain a lot or a little muscle from weight training and finds that they start with similar types of muscle fibers, which supports the idea that fiber type doesn’t decide how much muscle you can build.

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Source Study

Physiological Differences Between Low Versus High Skeletal Muscle Hypertrophic Responders to Resistance Exercise Training: Current Perspectives and Future Research Directions

Score: 1

DOI: 10.3389/fphys.2018.00834

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