When young men who don't normally exercise do eight weeks of weight training, their fast-twitch muscle fibers get bigger, but their slow-twitch fibers stay the same size and the overall mix of muscle types doesn't change.

33

Pro

0

Against

Evidence from Studies

Supporting (1)

33

Community contributions welcome

33

Fasted‐state skeletal muscle protein synthesis after resistance exercise is altered with training

Cross-Sectional Study

Human

2005 Oct 1

The study did the same type of exercise training as the claim and found exactly what the claim said: fast-twitch muscle fibers grew bigger after 8 weeks, while slow-twitch fibers didn't change.

Contradicting (0)

0

Community contributions welcome

No contradicting evidence found

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.

Source Study

Fasted‐state skeletal muscle protein synthesis after resistance exercise is altered with training

Score: 33

DOI: 10.1113/jphysiol.2005.093708

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