Fast Twich Fiber Training

Just a question. I see mentions of choosing loads and rep ranges and such due to the fiber makeup of the muscle. Isn’t this backwards? isn’t the fiber type a result of the work type that the muscle does?

No. Your muscle fiber type composition won’t change (at least not to a significant difference) based on the type of training you do. Certain methods of training are better at training certain muscle fiber types, but that does not change your physiological makeup - only the stimulation of those muscle fibers.

You have both fast and slow twitch muscle fibers. The ones you stimulate will be the ones that grow.

(waiting for someone to come in saying “whell acktuallee” and post studies)

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What Andrew said.

People who are good at something are good because of who they are, not because of what they do and how they train. You are born with certain parameters. If you are born a Toyota Corolla you will never race in Nascar.


Classic bell curve distribution. Extremes of fast or slow twitch genetics will be at either end of the bell. To be elite you will need to sit at one of those extremes and train hard for a relevant sport.
Most people will be at a balance of both, perhaps tending towards one end rather than the other.
With appropriate training they can become ok at both speed/strength and endurance. If training is aimed one way or the other they can be better than ok at one or the other.
Anyone will have noticed elite genetics at an earlly age, or have it pointed out to them.
If you are asking this question you are unlikely to be elite. So pick what you enjoy and aim to get the most out of it.

The dimension often missed IMHO is coordination which is critical to many sports.