Fight or Flight; which fiber types are used

An athletic trainer from a well respected Big 12 school wrote to me stating that fast twitch fibers do not get trained until after about 20 minutes of hard exercise. Is this true?

 If so, what about the body’s “fight or flight” response? Does this mean that when faced with danger, before we are able to sprint/run for safety, we are going to have to first stick around for 20 minutes or so and build up enough speed before we get out of harms way? This could be disatrous to your health!

Or, are your fast twitch fibers the “default” fiber types that get exercised early on in an exercise routine and the slow twitch fibers are the ones that come in to play after 20 minutes or so? Any body care to respond???

One Response to “Fight or Flight; which fiber types are used”

  1. Sharif Says:

    NO!! The fast twitch muscles are used first and they are what provide speed. Slow twitch muscles are what takes over after 20 min.

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